Filed 8/7/19
               CERTIFIED FOR PUBLICATION




 IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

                SECOND APPELLATE DISTRICT

                      DIVISION FOUR


VINCENT PINA,                          B285630 c/w B287285
                                       (Los Angeles County
Plaintiff and Appellant,               Super. Ct. No. BC526308)

v.

COUNTY OF LOS ANGELES et
al.,

Defendants and Respondents.


     APPEAL from a judgment of the Superior Court of Los
Angeles County, David S. Cunningham, Judge. Reversed
and remanded with directions.
     Medvei Law Group and Sebastian M. Medvei for
Plaintiff and Appellant.
     Collins Collins Muir + Stewart and James C. Jardin for
Defendants and Respondents.
                      INTRODUCTION
      Appellant Vincent Pina brought this personal injury
suit against respondents County of Los Angeles and Los
Angeles County Sheriff’s Department (collectively the
County), alleging, inter alia, that the County negligently
caused a bus on which he was a passenger to strike a pillar
in 2013. Appellant denied injury immediately after the
accident but reported pain soon thereafter, obtaining
treatment and diagnoses of spinal injury from Gary Chen,
M.D., and chiropractor Philemon Tam, D.C. At trial,
appellant admitted sustaining injury in a separate bus
accident in 2016, for which he sued the Los Angeles County
Metropolitan Transportation Authority (MTA). The County
also introduced evidence that appellant was struck by a car
in 2010. Nevertheless, Dr. Chen opined that the 2013
accident caused the injuries for which appellant claimed
damages, including injuries requiring future surgery.
Pursuant to Code of Civil Procedure section 2034.310,
subdivision (b), the trial court allowed the County to call
Robert Wilson, M.D. -- whom the MTA had retained to
examine appellant in his separate lawsuit, but whom the
County failed to designate as an expert in this case -- for the
purpose of impeaching Dr. Chen. Dr. Wilson testified that
Dr. Chen was wrong about the cause of appellant’s injuries
and the need for surgery.
      The jury found the County liable and awarded
appellant $5,000 in damages. The trial court denied
appellant’s motion challenging the adequacy of the damages,




                               2
relying in part on its conclusion that the jury believed
Dr. Wilson’s opinion that appellant would not require future
surgery. The court further denied appellant’s post-trial
motion for costs incurred in proving negligence and
causation of injury and granted several post-trial motions
filed by the County. The court awarded the County costs
(including attorney’s fees) under Code of Civil Procedure
sections 998, 1021.7, and 1032 and entered a second
judgment in the County’s favor.
       In his consolidated appeals from the judgment on the
verdict and from the court’s order on the parties’ post-trial
motions, appellant contends (1) the trial court prejudicially
erred in admitting Dr. Wilson’s testimony, which exceeded
the scope of permissible impeachment by an undesignated
expert witness; (2) the trial court prejudicially erred in
admitting other evidence concerning the cause of appellant’s
injuries and the amount of medical expenses he incurred; (3)
the County’s counsel prejudicially misrepresented the law
and the record during closing argument; (4) the jury’s
damages award was inadequate as a matter of law; (5) the
trial court erred in awarding attorney’s fees to the County
under Code of Civil Procedure section 1021.7; and (6) the
trial court erred in denying appellant’s motion for costs of
proof under Code of Civil Procedure section 2033.420.
       We agree that the testimony of Dr. Wilson went beyond
the scope of permissible impeachment by an undesignated
expert, and that the effect of admitting his opinion testimony
was prejudicial. We therefore reverse the judgment on the




                              3
verdict and remand for a new trial on all issues, with
instructions to the trial court to vacate its order on the
parties’ post-trial motions and the judgment entered
thereon. We address appellant’s additional contentions only
to the extent they regard issues likely to arise on retrial.

                 PROCEEDINGS BELOW
      A. Pretrial Proceedings
      In both an original and an amended complaint,
appellant sued the County for negligence under Vehicle Code
section 17001 and for failure to summon immediate medical
care under Government Code section 845.6, alleging that in
2013, while he was incarcerated in a County jail, the County
negligently injured him in a bus accident and failed to
summon immediate medical care in response to his
            1
requests.

1
       Government Code section 845.6 renders a public entity
immune from liability for “injury proximately caused by the
failure of [an] employee to furnish or obtain medical care for a
prisoner in his custody . . . .” Notwithstanding this immunity,
the statute imposes liability if the entity’s employee, acting
within the scope of employment, “knows or has reason to know
that the prisoner is in need of immediate medical care and . . .
fails to take reasonable action to summon such medical care.”
(Ibid.) The duty to summon immediate care is of a “limited
nature,” which “makes sense given that the statute carves that
duty out of a broad, general immunity.” (Castaneda v.
Department of Corrections & Rehabilitation (2013) 212
Cal.App.4th 1051, 1074.)




                                4
      In early 2014, three years before trial, the County
served responses to appellant’s first set of requests for
admission, asserting its inability to admit or deny that it
breached a duty of care to appellant by causing the 2013
accident and denying that the accident caused appellant
injury. At the time it served these responses, the County
was in possession of a medical report prepared by Dr. Gary
Chen, whom appellant had consulted in connection with his
complaints of injury. A year later, in March 2015, in
response to appellant’s second set of requests for admission,
the County admitted it was negligent when its employee
caused the 2013 accident.
      In August 2015, appellant served an expert witness list
designating Dr. Chen and chiropractor Philemon Tam.
Several days later, the County served an expert witness list
and declaration identifying a single expert: Jacob Tauber,
M.D. The declaration stated that the County expected
Dr. Tauber to testify at trial regarding, inter alia, appellant’s
“future orthopedic medical treatment” and “the
reasonableness and necessity of . . . future orthopedic
medical care and related expenses.” In April 2016, however,
in opposition to several motions in limine filed by appellant,
the County represented it did not intend to call any expert
witness at trial.
      In October 2016, the parties first appeared for trial
before Judge Joseph R. Kalin. The court found the case not
ready for trial because appellant had newly served the
County with a second report by Dr. Chen -- prepared after




                                5
appellant was in a second bus accident earlier that year --
finding a disc herniation and recommending surgery. The
court noted the County might be entitled to call an expert
witness regarding Dr. Chen’s new opinions. The parties
stipulated to reopen discovery. The County then re-deposed
appellant, who testified that although he hoped to avoid
surgery by healing without it, he might need to obtain the
surgery recommended by Dr. Chen.
      The month before trial, the County served an offer to
compromise under Code of Civil Procedure section 998,
offering appellant a judgment in his favor for $5,000,
“inclusive of costs and expenses, attorneys’ fees and
interest.” Appellant did not accept the offer. In a settlement
communication sent the same day, appellant’s counsel
estimated the value of the case as above $500,000, relying in
part on the County’s alleged exposure to damages resulting
from Dr. Chen’s recommendation for surgery.
      The parties appeared for trial before Judge David S.
Cunningham, III, in April 2017. At a hearing on the parties’
motions in limine, appellant argued that the County should
be barred from presenting expert opinion testimony from
Dr. Robert Wilson, an orthopedic surgeon whom the MTA
had retained to examine appellant in his separate lawsuit
concerning the 2016 accident, but whom the County had not
designated as an expert witness in this case. Asking the
County to brief the issue, the court tentatively ruled that
Dr. Wilson’s testimony would be allowed only to impeach
appellant’s experts.




                              6
      During the same hearing, the County’s counsel
acknowledged that the County’s admission, in discovery,
that it was “negligent” in causing the 2013 accident conceded
the issue of breach of a duty of care. The next day, appellant
voluntarily dismissed his cause of action for failure to
summon immediate medical care.

       B. Trial
             1. The 2013 Accident
       Appellant testified that in May 2013, he was arrested
and incarcerated in County jail pending resolution of charges
against him. On June 28, 2013, he was taken to and from
court on a County bus. While pulling forward into a parking
spot at what appellant estimated to be a speed of 5 to 10
miles per hour, the bus collided with a structural beam,
causing the bus to sway. Due to the bus’s swaying, the
passenger to whom appellant was chained pulled appellant
to the left, out of his seat, and onto the floor. Appellant
testified inconsistently about the manner in which his body
                               2
struck the interior of the bus. Appellant confirmed that in a
2
       On cross-examination, appellant testified that his right
shoulder hit the right side of the bus. Before the jury, the
County’s counsel read deposition testimony in which appellant
claimed, in contrast, that his left shoulder was the only part of
his body to strike anything inside the bus. Additionally,
appellant confirmed that according to the transcript of a
subsequent deposition in his separate lawsuit, he claimed to have
hit his ribs during the accident. Appellant then testified that he
believed his left shoulder hit the seat in front of him.




                                7
videotaped interview conducted immediately after the
accident, he denied suffering any injury. The video was
played for the jury.
      The County called the bus’s driver, Deputy Daniel
Martin Del Campo, who testified that the bus scraped
against a pillar as he was backing out of a parking space at a
speed of one or two miles per hour. The County also called
Sergeant Kevin Zaborniak, who testified that he and another
officer interviewed the passengers within an hour of the
accident and arranged for those who claimed injury to see
medical staff.

            2. Appellant’s Complaints in Custody
       Appellant testified he began to feel pain almost
immediately after his videotaped interview, before he got
back on the bus. He reported the pain to an unidentified
female deputy, who told him to report it upon arrival back at
jail. A nurse dispensed pills in the jail that evening, but
appellant said nothing to her about pain. The next court
day, appellant reported pain to his criminal defense
attorney, who obtained a court order requiring the County to
provide appellant a medical examination. When taken to
nurse practitioner Nachet Harris several days later,
appellant told her he was in pain and needed to see a doctor
to determine if he needed an X-ray, but she told him no
doctor was available.
       The County called nurse practitioner Harris, who
testified she was qualified to conduct physical examinations




                              8
and refer patients for X-rays, but appellant refused to be
examined by her, claiming he needed to be examined by a
physician. The County also called Dr. Nickolay Teophilov, a
physician with supervisory responsibilities concerning
medical care in County jails, who similarly testified that
nurse practitioner Harris was qualified to perform a medical
examination and order X-rays. Dr. Teophilov further
testified that incarcerated persons could request medical
care by submitting a written form or by approaching a “pill
call” nurse. Appellant did neither.

            3. Appellant’s Medical Treatment
      Appellant testified that within weeks of his release
from the County’s custody (upon acquittal in his criminal
case), he saw Gary Chen, M.D., to whom his counsel referred
him. Appellant claimed to have truthfully and completely
disclosed his medical history to Dr. Chen. He completed
about 20 sessions of physical therapy on Dr. Chen’s recom-
mendation, discontinuing the physical therapy in part
because his pain decreased. Although Dr. Chen recom-
mended that appellant obtain an MRI, he did not then
obtain one.
      The next year, in response to an alleged increase in
pain, appellant began treatment with chiropractor Philemon
Tam. Appellant claimed to have truthfully and completely
disclosed his medical history to Tam. He completed about 20
sessions of chiropractic treatment with Tam, again disconti-
nuing treatment in part because his pain decreased.




                             9
      Appellant testified that his pain increased after he was
involved in another bus accident in 2016. He confirmed that
he was injured in the 2016 accident. After the accident, he
saw Dr. Chen again and obtained an MRI for the first time.
He expressed his intent to “at some point” follow Dr. Chen’s
recommendation to obtain surgery.

            4. The 2010 Accident
      The court held an Evidence Code section 402 hearing
on the County’s proffer of evidence to impeach appellant’s
testimony that he had disclosed his complete medical history
to Dr. Chen and Tam. Specifically, the County offered to
show that in 2010, appellant had been hit by a car and had
reported pain all over his body. Appellant confirmed that a
2010 traffic collision report listed his name, former address,
and birth date, but claimed not to recall the reported
accident. Appellant’s counsel argued for exclusion of
evidence concerning the 2010 accident on the ground that
the County had disclosed no such evidence in response to
appellant’s form interrogatory No. 16.1, which asked the
County to identify all evidence that any third party
contributed to appellant’s claimed injuries or damages. The
court ruled the County could introduce evidence concerning
the 2010 accident for impeachment.
      After the hearing, appellant testified he did not recall
being struck by a car in 2010, rolling up onto the hood of the
car and smashing into its windshield, falling to the
pavement, telling the investigating officer that he felt pain




                              10
everywhere in his body, or being taken to an emergency
room. He confirmed he did not report such an accident to
Dr. Chen or Tam.
      The County called Long Beach Police Department
officer Mark Mesun, who testified he investigated a 2010 car
accident but recalled little about it and did not recognize
appellant in court. He further testified the accident victim
reported that he hurt everywhere after being struck by a car
while running across a street. He identified the California
identification number provided by the accident victim.
      The County also called attorney Philip Allen, counsel
for the MTA in appellant’s separate lawsuit, who testified
appellant produced his California identification card when
Mr. Allen deposed him. Appellant’s identification card,
which was admitted into evidence, bore the same number
provided by the 2010 accident victim.

            5. Expert Witnesses
      Appellant called Dr. Chen to testify about the cause of
his injuries, his alleged future medical expenses, and the
expenses appellant had already incurred for Dr. Chen’s
treatment. Dr. Chen testified that he was “strongly
suspicious,” based on X-rays performed in 2013 and 2016
and on the MRI results obtained in 2016, that the 2013
accident was the cause of injuries to appellant’s cervical
(neck) and lumbar (lower back) spine. He based this
conclusion in part on his finding of significant progression in
the X-ray results between 2013 and 2016, explaining that




                              11
the 2016 X-rays showed increased narrowing of the discs and
increased formation of bone spurs.
      Dr. Chen further testified that appellant would need
surgery to remove both a disc herniation and a disc
protrusion. Dr. Chen based this conclusion largely on his
observation that the MRI results showed the disc herniation
compressing a nerve. He estimated the cost of surgery to
remove a disc as $90,500. He testified he did not know the
total sum appellant owed him for past treatment, but
confirmed that “around $12,000 sound[ed] accurate.”
Dr. Chen did not testify about the reasonableness of his bills,
which were not offered into evidence.
      On cross-examination, Dr. Chen confirmed that X-rays
are insufficient for a reliable assessment of disc injuries,
which requires MRI results. He further confirmed that the
only MRI results he reviewed, which were obtained after the
2016 accident, suggested appellant’s disc protrusion was
recent. Although appellant told Dr. Chen the 2016 accident
occurred, Dr. Chen knew no details about the accident and
might have been able to give a more precise opinion if he had
known them. Further, he had no information about
appellant’s medical condition prior to the 2013 X-rays other
than what appellant told him. Appellant did not tell
Dr. Chen he was struck by a car in 2010, which, if true,
might have changed Dr. Chen’s opinion about the cause of
appellant’s injuries. Confirming that he did not know what
the bus struck during the 2013 accident or how hard it
struck it, Dr. Chen disclaimed any intent (or qualification) to




                              12
opine on “biomechanical analysis,” meaning the measure of
force applied to a body.
      Appellant also called chiropractor Tam, who testified
that through his physical examination of appellant, he
determined that appellant sustained sprains on his cervical
and lumbar spine and on his left shoulder in the 2013
accident. When Tam asked if appellant had been in any
previous accidents, appellant said he had not. Appellant’s
condition improved by 85 to 90 percent after his physical
therapy with Tam. Tam testified appellant owed him
$2,070. Tam’s bills for the same sum were admitted into
evidence.
      The court allowed the County to call Dr. Wilson, but
stated its intention to limit his testimony to impeaching
Dr. Chen within the meaning of Code of Civil Procedure
section 2034.310 and Kennemur v. State of California (1982)
133 Cal.App.3d 907 (Kennemur), cautioning the County that
it would not be permitted to elicit rebuttal opinion. The
County’s counsel asked Dr. Wilson to identify a foundational
fact upon which Dr. Chen relied that Dr. Wilson believed to
be false or non-existent. In response, Dr. Wilson testified
that Dr. Chen’s opinion that the 2013 accident caused a disc
pathology was not reasonable because appellant lacked “a
presentation or a history of an injury that would support
that there was any significant lumbar or any other major
injury.” Appellant moved to strike this testimony as
exceeding the scope of permissible impeachment, but the




                             13
                          3
court denied the motion. Dr. Wilson then rephrased his
prior testimony, asserting that Dr. Chen’s opinion that the
2013 accident caused an injury to appellant’s back was not
“supported by the medical records or the mechanics or the
                                     4
initial findings or presentation.” Dr. Wilson explained by
testifying, inter alia, that 99 percent of disc protrusions are
caused by degenerative change rather than trauma,
referencing several vaguely identified research studies.
      The County’s counsel asked Dr. Wilson to identify an
additional foundational fact on which Dr. Chen relied that
Dr. Wilson believed false or non-existent. In response,
Dr. Wilson testified that Dr. Chen’s finding of a significant
change between the 2013 and 2016 X-rays, and his
interpretation of that change as reflecting a traumatic event,
were “not correct” and were not “supported by medical
knowledge or medical literature.” He explained by
testifying, inter alia, that a finding of significant change in



3
      The court later granted appellant’s motion to strike
Dr. Wilson’s testimony that appellant possibly sustained soft
tissue injuries. The court otherwise allowed Dr. Wilson’s
testimony, over repeated motions to strike and requests to lodge
a standing objection, noting its view that appellant had preserved
his objections to Dr. Wilson’s testimony for appeal.
4
      Dr. Wilson later rephrased this testimony again, asserting
that Dr. Chen’s finding of significant injury due to the 2013
accident was not medically substantiated by the MRI results, the
X-rays, or the presentation of appellant’s injury.




                                14
the X-rays would have required evidence of a bone fracture
or major ligament disruption.
       The County’s counsel asked Dr. Wilson to identify “the
third point that [he had] a difference of opinion on with
Dr. Chen.” Dr. Wilson responded by contrasting Dr. Chen’s
opinion that appellant would require future surgery to
address his injuries resulting from the 2013 accident with
Dr. Wilson’s own determination, after examining appellant,
that appellant “had no indications of needing surgery.” He
testified that appellant had no significant nerve compres-
sion, explaining on cross-examination that although the MRI
results showed narrowing of a canal through which a nerve
passed, the narrowing was insufficient to compress the
nerve. He further testified that the American Academy of
Orthopaedic Surgeons had found surgery generally
unwarranted for back pain associated with degenerative disc
disease.
       Dr. Wilson further testified that although appellant
might develop a need for surgery, the need would not be
caused by the 2013 accident, which applied a lesser degree of
force to appellant’s back than he would have experienced
picking up a heavy object from the trunk of a car. Dr. Wilson
added that because the average person experiences greater
forces multiple times per month, it would not be “fair” to
attribute appellant’s injuries to the 2013 accident.




                             15
            6. Closing Arguments
      At the conclusion of the parties’ presentation of
evidence, appellant moved into evidence the County’s
responses to requests for admission. When arguing, in
closing, that the jury should find the County negligent,
appellant’s counsel relied solely on the County’s admission of
negligence. He further argued that the 2013 accident caused
appellant’s injuries, relying substantially on Dr. Chen’s
opinions.
      In the County’s closing argument, its counsel acknow-
ledged that it had admitted the elements of negligence other
than causation of damages, referencing CACI instruction No.
                                 5
424 (negligence not contested). The County’s counsel
commented that appellant was required to “prove that his
injuries, if he had them, were caused by our bus accident in
2013 and that all of the future medicals, past medicals, pain
and suffering, is all our fault.” He argued that appellant had
failed to meet this burden, reminding the jury, inter alia,
that Dr. Wilson had testified that Dr. Chen’s opinions were
invalid, purportedly by explaining that they were based on
false facts.
       The County’s counsel referred (erroneously) to evidence
of bills from Dr. Chen for $1,200 or $1,020. He also

5
      The court’s instructions to the jury were neither reported
nor included in the appellate record. However, before appellant
rested, the court stated without objection that it would deliver
CACI No. 424.




                                16
mistakenly referred to bills from chiropractor Tam totaling
$7,000, before correctly identifying the $2,070 total. He
concluded his argument by asking the jury either to return a
defense verdict or to award appellant only $1,020 for
Dr. Chen’s treatment and $2,070 for Tam’s treatment.
      Appellant’s counsel requested a sidebar at the
conclusion of the County’s closing argument. He objected to
an alleged misstatement of law by the County’s counsel
concerning the County’s burden to prove a contributory or
superseding cause. He also objected to opposing counsel’s
reference to $1,020 in bills from Dr. Chen, arguing it
misstated Dr. Chen’s testimony that appellant owed him
around $12,000. Without ruling on the merits of the
objections, the court declined to admonish the jury, deferring
to appellant’s counsel to argue the matters in rebuttal.
      Appellant’s counsel made no attempt to clarify
Dr. Chen’s testimony about his bills in rebuttal, instead
merely noting that the jury instructions explained the
burden of proof on contributing and superseding causes.

            7. Jury Deliberations and Verdict
      During its deliberations, the jury submitted a written
request to be given “exactly how much medical expenses for
Tam and Chen,” asking, “[I]s it 2070 and 1200?” The court
returned the following stipulated response: “The parties
stipulate that Dr. Tam’s bill for past medical expenses totals
$2070. As to Dr. Chen, the court directs you to jury
instruction #5011.” CACI No. 5011 instructed the jury that




                              17
it could request a reading of testimony. The jury made no
such request, instead returning a verdict five minutes after
receiving the response. In response to questions posed by
the parties’ special verdict form, the jury answered, inter
alia, that (1) the County was negligent; (2) the County’s
negligence was a substantial factor in causing appellant
harm; and (3) appellant’s total damages equaled $5,000,
consisting of $3,270 in past medical expenses and $1,730 in
past noneconomic loss. The court entered judgment on the
verdict, from which appellant timely appealed.

     C. Post-Trial Proceedings
     Appellant moved for a new trial on the amount of
damages, arguing the jury’s award was inadequate as a
matter of law. Appellant also moved to recover costs of proof
under Code of Civil Procedure section 2033.420, on the
ground that he had proved matters the County had failed to
admit in response to his requests for admission, viz., that the
County was negligent and that its negligence caused him
          6
injury. Finally, appellant claimed ordinary costs in original
and amended memoranda of costs.

6
       Code of Civil Procedure section 2033.420, subdivision (a),
provides that “[i]f a party fails to admit . . . the truth of any
matter when requested to do so [in a request for admission], and
if the party requesting that admission thereafter proves . . . the
truth of that matter, the party requesting the admission may
move the court for an order requiring the party to whom the
request was directed to pay the reasonable expenses incurred in
(Fn. is continued on the next page.)




                                       18
     The County filed its own memorandum of costs, along
with a motion to be declared the prevailing party and
awarded costs (including $25,497.50 in attorney’s fees) under
Code of Civil Procedure sections 998 and 1032. Separately,
the County moved under Code of Civil Procedure section
1021.7 to recover $12,252.75 in attorney’s fees incurred in
connection with appellant’s voluntarily dismissed cause of
                                                           7
action for failure to summon immediate medical care.
      At a hearing on the parties’ post-trial motions, the trial
court denied appellant’s motion for a new trial, reasoning,
inter alia, that the jury could reasonably have discredited
Dr. Chen’s opinions. The court recalled Dr. Wilson’s
testimony that “the future surgery Dr. Chen advocated for
would not be medically justified and would not be beneficial
to [appellant],” commenting, “The jury heard that. I can
only conclude that the jury believed it.” The court also

making that proof, including reasonable attorney’s fees.” The
statute requires the court to grant the motion unless it makes
any of four enumerated findings, including that “[t]he party
failing to make the admission had reasonable ground to believe
that that party would prevail on the matter” or that “[t]here was
other good reason for the failure to admit.” (Id. subd. (b).)
7
       Code of Civil Procedure section 1021.7 provides that “[i]n
any action for damages arising out of the performance of a peace
officer’s duties, brought . . . against a public entity employing a
peace officer . . . the court may, in its discretion, award
reasonable attorney’s fees to the defendant or defendants as part
of the costs, upon a finding by the court that the action was not
filed or maintained in good faith and with reasonable cause.”




                                 19
denied appellant’s motion for costs of proof, reasoning that
the County had reasonable ground to believe it would prevail
on the matters when it failed to admit them, and that there
were other (unspecified) good reasons for the County’s
                         8
failure to admit them.



8
       The trial court did not expressly consider whether
appellant had proved breach of duty within the meaning of Code
of Civil Procedure section 2033.420. It would have been within
the court’s discretion to find the matter not proved, due to the
County’s concessions regarding breach before and during trial
and appellant’s failure to present evidence on the matter other
than the County’s admission of negligence. (See Stull v. Sparrow
(2001) 92 Cal.App.4th 860, 864-868 [plaintiff not entitled to costs
of proving defendants’ fault for car accident where defendants
conceded fault immediately before trial]; Wagy v. Brown (1994)
24 Cal.App.4th 1, 4, 6 [plaintiff not entitled to costs of proving
negligence where defendant conceded negligence for purpose of
arbitration].) The County did not concede that the 2013 accident
caused appellant injury. However, the trial court’s finding that
the County had reasonable ground to believe, at the time it
served its responses to appellant’s requests for admission, that it
would prevail on the matter was supported by the County’s
explanation that it was then aware of (1) appellant’s denial of
injury immediately after the accident; (2) the fact that out of the
17 other passengers, 15 reported no injury and the remaining two
reported only a bruised knee and a stiff neck; (3) investigators’
finding that the accident consisted of a low-speed scrape against
a pillar; and (4) appellant’s failure to seek medical care when in
custody, aside from obtaining a court order for a medical
examination with which he declined to proceed after learning a
nurse practitioner would conduct it.




                                20
      At the same hearing, the court granted the County’s
motions for prevailing party status, costs, and attorney’s
fees. The court interpreted Code of Civil Procedure section
998, subdivision (e) to allow the court to deduct costs
(including attorney’s fees) from appellant’s damages award
before determining which party prevailed, within the
meaning of Code of Civil Procedure section 1032, by
                                       9
obtaining a net monetary recovery. The court added $576
in undisputed costs incurred by appellant to his $5,000

9
      As appellant unsuccessfully argued before the trial court,
the plain language of Code of Civil Procedure section 998 requires
a court to find the judgment less favorable than the offer before
deducting costs under that section from the damages award.
(Code Civ. Proc., § 998, subd. (c)(1) [“If an offer made by a
defendant is not accepted and the plaintiff fails to obtain a more
favorable judgment or award, the plaintiff . . . shall pay the
defendant’s costs from the time of the offer”], id., § 998, subd. (e)
[authorizing deduction of costs “under this section” from the
plaintiff’s damages award if the plaintiff does not accept the
defendant’s offer and “fails to obtain a more favorable judgment
or award”].) Absent deductions, appellant’s judgment was more
favorable than the County’s offer -- the value of the offer was
limited to $5,000, inclusive of costs, whereas the value of
appellant’s judgment included both the $5,000 damages award
and appellant’s undisputed preoffer costs. (Weil & Brown, Cal.
Practice Guide: Civil Procedure Before Trial (The Rutter Group
2018) ¶ 12:655, p. 12(II)-48 [“[P]laintiff’s preoffer costs are
included [in the value of the judgment] in computing whether the
judgment is ‘more favorable’ than the § 998 offer”], citing
Heritage Engineering Construction, Inc. v. City of Industry (1998)
65 Cal.App.4th 1435, 1441.)




                                 21
damages award. From this $5,576 sum, the court deducted
$42,508.15 in costs claimed by the County (including
$25,497.50 in attorney’s fees), yielding a net monetary
                                                10
recovery of $36,932.15 in the County’s favor. The court
relied on this net monetary recovery to declare the County
the prevailing party. The court issued an order on the post-
trial motions, from which appellant appealed, and entered a
second judgment, this time for the County.

                       DISCUSSION
     A. Admission of Dr. Wilson’s Testimony
     Appellant asserts the trial court abused its discretion
in admitting testimony from Dr. Wilson that exceeded the
scope of permissible impeachment by an undesignated
expert. He further contends the erroneous admission of
Dr. Wilson’s testimony prejudiced him, as the jury’s damages
award suggests it believed Dr. Wilson’s opinions that the


10
      The basis for the award of attorney’s fees is unclear to the
extent the award exceeded the $12,252.75 the County sought
under Code of Civil Procedure section 1021.7. Costs allowable
under Code of Civil Procedure sections 998 and 1032 include
attorney’s fees only to the extent separately authorized by other
sources. (Weil & Brown, Cal. Practice Guide: Civil Procedure
Before Trial, supra, ¶ 12:648.5a, p. 12(II)-45 [“CCP § 998 does not
provide greater rights to attorney fees than provided by the
underlying statute or contract”]; Code Civ. Proc., § 1033.5, subd.
(a)(10) [attorney’s fees allowable as costs only when authorized by
contract, statute, or law].)




                                22
2013 accident did not cause appellant’s more serious injuries
and that appellant would not require future surgery.

            1. Standard of Review
      “Except to the extent the trial court bases its ruling on
a conclusion of law (which we review de novo), we review its
ruling excluding or admitting expert testimony for abuse of
discretion.” (Sargon Enterprises, Inc. v. University of
Southern California (2012) 55 Cal.4th 747, 773.) “‘Action
that transgresses the confines of the applicable principles of
law is outside the scope of discretion and we call such action
an “abuse” of discretion.’” (Ibid., quoting City of Sacramento
v. Drew (1989) 207 Cal.App.3d 1287, 1297.) Error in the
admission of evidence is reversible only if there is a
reasonable probability -- meaning a possibility that is more
than abstract -- that the appellant would have obtained a
more favorable result had the evidence been excluded.
(Wilson v. Southern California Edison Co. (2018) 21
Cal.App.5th 786, 808 (Wilson); accord Basham v. Babcock
(1996) 44 Cal.App.4th 1717, 1723-1724 [applying reasonable
probability standard to reverse, due to erroneous admission
of testimony concerning causation of injury from improperly
designated expert]; cf. Province v. Center for Women’s Health
& Family Birth (1993) 20 Cal.App.4th 1673, 1681-1684
[reversing due to erroneous admission of expert opinion
testimony from percipient witness not designated as an
expert, noting “[j]uror declarations suggest[ed] that some
jurors may have been swayed by such testimony”], id. at




                              23
p. 1683, disapproved on other grounds in Heller v. Norcal
Mutual Ins. Co. (1994) 8 Cal.4th 30, 41.) A “‘reasonable’”
probability under this test is one sufficient to undermine the
reviewing court’s confidence in the outcome. (See In re
Richards (2016) 63 Cal.4th 291, 312-313 (Richards).)

            2. Governing Principles
     Generally, on objection of any party who has “made a
complete and timely compliance” with the expert exchange
statute, the trial court “shall exclude from evidence the
expert opinion of any witness that is offered by any party
who has unreasonably failed,” inter alia, to designate that
                                    11
expert in its expert witness list. (Code Civ. Proc.,
§ 2034.300.) The same exclusionary rule applies where “a
party wishes to call an expert not included on the original
list and the party has unreasonably failed to obtain
permission to augment its list . . . .” (Weil & Brown, Cal.
Practice Guide: Civil Procedure Before Trial, supra, ¶
8:1708, p. 8J-29, citing Richaud v. Jennings (1993) 16
Cal.App.4th 81, 85.)
      Notwithstanding the foregoing exclusionary rule, a
party “may call as a witness at trial an expert not previously
designated by that party . . . [¶] . . . [¶] . . . to impeach the
testimony of an expert witness offered by any other party at

11
      The County does not argue that appellant failed to make “a
complete and timely compliance” with the expert exchange
requirements.




                               24
the trial.” (Code Civ. Proc., § 2034.310, subd. (b).) Although
the term “impeach[]” is susceptible to an interpretation
encompassing the offering of contrary opinion, permissible
impeachment by an undesignated expert is narrower in
scope. (See Kennemur, supra, 133 Cal.App.3d at pp. 921-
922.) Indeed, the Legislature has codified the distinction
between permissible impeachment and contrary opinion:
“This impeachment may include testimony to the falsity or
nonexistence of any fact used as the foundation for any
opinion by any other party’s expert witness, but may not
include testimony that contradicts the opinion.” (Code Civ.
Proc., § 2034.310, subd. (b).) “[R]ather than broadly
construing what a foundational ‘fact’ is, the term should be
strictly construed by the trial court to prevent a party from
offering a contrary opinion of his expert under the guise of
impeachment.” (Kennemur, supra, at p. 924; see also id. at
pp. 911-912, 922, 924-925 [defense expert’s opinion that tire
tracks crossing road’s centerline were made by plaintiff’s car
-- in support of a further opinion that the plaintiff caused an
accident by abruptly steering into oncoming traffic -- was not
a foundational fact but instead a subordinate opinion based
on foundational facts, viz., photographs of the tracks and a
percipient witness’s testimony that the plaintiff steered
across the centerline].)
       Courts applying this limitation have consistently
affirmed the exclusion of testimony opining that an opposing
expert misunderstood or misapplied the relevant body of
expert knowledge. (See Collins v. Navistar, Inc. (2013) 214




                              25
Cal.App.4th 1486, 1495-1496, 1517 (Collins) [affirming
exclusion of testimony that opposing expert’s statistical
opinions were inaccurate, and that databases on which she
relied were unreliable due to omitting data]; Mizel v. City of
Santa Monica (2001) 93 Cal.App.4th 1059, 1066-1068 (Mizel)
[affirming exclusion of testimony that a person will smell of
alcohol only after a particular level of alcohol consumption,
where opposing expert had denied awareness of studies
supporting that conclusion and relied on personal education
and experience to opine otherwise]; Howard Contracting,
Inc. v. G.A. MacDonald Construction Co., Inc. (1998) 71
Cal.App.4th 38, 53-54 (Howard) [affirming exclusion of
testimony that opposing expert misapplied accepted formula
in calculating construction delay damages, which trial court
deemed “impermissible contrary opinion concerning accepted
accounting practices used in applying” the formula]; Fish v.
Guevara (1993) 12 Cal.App.4th 142, 145-146 (Fish)
[affirming exclusion of testimony that opposing experts,
applying their knowledge, training, and review of third-party
studies rather than direct observation, inaccurately assessed
permeability rate of soil].)

           3. Analysis
      We agree with appellant and the trial court that
Dr. Wilson’s testimony should have been limited to
impeachment within the meaning of Code of Civil Procedure
section 2034.310. Although the County does not expressly
argue otherwise, it asserts, with no citation to authority,




                              26
that the trial court’s admission of Dr. Wilson’s testimony
“was consistent with . . . the fundamental interests of justice
in permitting [the County] to respond to late-disclosed
evidence,” viz., evidence of appellant’s need for surgery.
Before the trial court, the County represented that it
retained Dr. Wilson in response to appellant’s disclosure of
his intent to claim that the 2016 accident exacerbated
injuries sustained in the 2013 accident. Both this
anticipated claim and Dr. Chen’s recommendation for
surgery were discussed on the record approximately six
months before trial, when Judge Kalin suggested the County
might be entitled to retain an opposing expert and the
parties stipulated to reopen discovery. The County had
ample opportunity in the intervening months -- during which
appellant confirmed at deposition that he might obtain the
recommended surgery, and appellant’s counsel relied on
expected damages for that surgery in settlement
negotiations -- to move to augment its expert witness list to
                 12
add Dr. Wilson. So far as the record discloses, the County
neither made such a motion nor offered Dr. Wilson for
deposition. The court thus properly invoked the limitation of
Code of Civil Procedure section 2034.310.


12
      Neither the record nor the County’s appellate brief
discloses why the County did not seek to call the expert witness
already designated on its list, Dr. Tauber, whom the County
reportedly retained to testify regarding, inter alia, appellant’s
need for future treatment.




                                27
      However, the court exceeded its discretion in applying
that limitation, liberally construing the term “foundational
fact[]” in a manner that allowed the County to offer contrary
opinions under the guise of impeachment. Dr. Wilson
contradicted Dr. Chen’s causation opinion -- viz., that the
2013 accident caused appellant significant injury -- by
opining that it was not medically substantiated by the
X-rays, the MRI results, and the presentation of appellant’s
injuries. Dr. Wilson supported this contrary causation
opinion with two additional opinions, testifying (1) that
“medical knowledge [and] medical literature” supported
neither Dr. Chen’s finding (in support of his causation
opinion) of a significant change between the 2013 and 2016
X-rays, nor his interpretation of that change as reflecting a
traumatic event; and (2) that the force applied to appellant’s
body in the 2013 accident was insufficient to cause
appellant’s injuries.
      These contrary opinions did not concern the falsity or
non-existence of foundational facts on which Dr. Chen relied.
Dr. Chen expressly disclaimed any opinion on the degree of
force involved in the 2013 accident, admitting he did not
know how hard the bus struck the pillar. Thus, Dr. Wilson’s
opinion regarding the degree of force had no relation to the
factual foundations of Dr. Chen’s opinions. In delivering his
other causation opinions, Dr. Wilson similarly failed to
challenge the veracity of the facts on which Dr. Chen relied.
Instead, he testified to the effect that Dr. Chen misunder-
stood or misapplied medical science; Dr. Wilson then




                              28
advanced a contrary understanding of that science based,
inter alia, on research studies purportedly establishing that
99 percent of disc protrusions are caused by degenerative
change and unspecified sources establishing that a bone
fracture or major ligament disruption is necessary to find a
significant change between X-rays. This testimony exceeded
the scope of permissible impeachment. (See Collins, supra,
214 Cal.App.4th at pp. 1495-1496, 1517; Mizel, supra, 93
Cal.App.4th at pp. 1066-1068; Howard, supra, 71
Cal.App.4th at pp. 53, 54; Fish, supra, 12 Cal.App.4th at
pp. 145-146.)
      Dr. Wilson also contradicted Dr. Chen’s opinion that
appellant would require future surgery, opining, in response
to a request from the County’s counsel to identify “a
difference of opinion” with Dr. Chen, that appellant “had no
indications of needing surgery.” Dr. Wilson supported this
contrary opinion with matters unrelated to the factual
foundations of Dr. Chen’s opinion, including his independent
examination of appellant (referenced only generally, without
mention of any factual findings contrary to those on which
Dr. Chen relied) and a purported conclusion of the American
Academy of Orthopaedic Surgeons that surgery is generally
unwarranted for back pain associated with degenerative disc
disease. As the trial court acknowledged in denying
appellant’s motion for a new trial, the thrust of Dr. Wilson’s
testimony on this point was that the recommended surgery
“would not be medically justified and would not be beneficial
to [appellant].” As noted, disagreement with an opposing




                              29
expert’s understanding or application of medical science
exceeds the scope of permissible impeachment. (See Collins,
supra, 214 Cal.App.4th at pp. 1495-1496, 1517; Mizel, supra,
93 Cal.App.4th 1059 at pp. 1066-1068; Howard, supra, 71
Cal.App.4th at pp. 53-54; Fish, supra, 12 Cal.App.4th at
pp. 145-146.)
      In contrast, Dr. Wilson’s testimony that the MRI
results did not show nerve compression permissibly
impeached Dr. Chen’s testimony regarding what the MRI
showed -- a foundational fact relevant to Dr. Chen’s medical
opinions. (See Stark v. City of Los Angeles (1985) 168
Cal.App.3d 276, 281 [undesignated expert permissibly
impeached opposing expert by testifying to the falsity of the
opposing expert’s description of a police siren’s audibility
range, on which the opposing expert relied to opine that the
plaintiff likely would not have heard the siren even if the
police had activated it], superseded by statute on another
ground as stated in Thomas v. City of Richmond (1995) 9
Cal.4th 1154, 1161-1162; cf. Howard, supra, 71 Cal.App.4th
at p. 54 [although undesignated experts were properly
barred from contradicting an opposing expert regarding
accepted accounting practices used in applying a formula,
permissible impeachment could have included testimony
challenging the accuracy of the opposing expert’s
calculations or providing substitute figures]; Kennemur,
supra, 133 Cal.App.3d at p. 925 [where defense expert relied
on photographs of tire tracks to opine that tracks were made
by plaintiff’s car, permissible impeachment could have




                             30
included testimony “that the photographs were false, i.e.,
that they did not accurately depict the accident scene”].) As
explained, however, Dr. Wilson’s testimony went well beyond
this permissible impeachment of a foundational fact.
       We reject the County’s argument that Dr. Wilson
permissibly impeached Dr. Chen by testifying to the
“absence of any evidence” supporting his opinions. The
argument relies on the implicit premise that “the existence
of supporting evidence” is a foundational fact. Such a broad,
abstract interpretation of the term would render the
statutory distinction between impeachment and contrary
opinion meaningless, giving parties free rein to disregard the
expert disclosure requirements and thereby deprive their
opponents of crucial opportunities for pretrial discovery.
(See Kennemur, supra, 133 Cal.App.3d at p. 924 [liberal
interpretation of “foundational fact” would thwart legislative
intent for parties to receive reasonable notice of opposing
expert testimony]; Boston v. Penny Lane Centers, Inc. (2009)
170 Cal.App.4th 936, 951 [the Legislature enacted expert
disclosure requirements in response to the need for pretrial
discovery with respect to expert witnesses, which is greater
than with respect to lay witnesses], citing Bonds v. Roy
(1999) 20 Cal.4th 140, 147.)
       Notably, the County does not argue that if Dr. Wilson’s
testimony was improperly admitted, any error was not
prejudicial. Nor could it. Dr. Wilson’s contrary causation
opinions addressed the core issues of the County’s defense,
viz., the extent to which the 2013 accident caused appellant’s




                              31
injuries and the extent of those injuries. The County
presented little evidence on the issues aside from
Dr. Wilson’s opinions, instead focusing on impeaching
appellant’s witnesses. Further, Dr. Wilson’s contrary
opinion regarding appellant’s need for surgery addressed the
largest component of appellant’s claimed damages -- Dr.
Chen estimated the cost of a single of two recommended
surgeries as $90,500, far exceeding the bills for past
treatment to which Dr. Chen and Tam testified. In
explaining its denial of appellant’s motion challenging the
adequacy of the damages award, the trial court concluded
that the jury appeared to have believed Dr. Wilson’s opinion
that the recommended surgery “would not be medically
justified and would not be beneficial to [appellant].” On this
record, we cannot be confident the jury would have returned
the same verdict had the trial court excluded Dr. Wilson’s
                             13
contrary opinions. (See, e.g., Richards, supra, 63 Cal.4th
at pp. 312-313; Wilson, supra, 21 Cal.App.5th at p. 808.)

13
      Even had the trial court excluded Dr. Wilson’s contrary
opinions, the court would not have been compelled to grant
appellant’s motion challenging the adequacy of the damages
award. (See, e.g., Rayii v. Gatica (2013) 218 Cal.App.4th 1402,
1415-1416 [trial court’s denial of new trial motion based on
inadequate damages must be affirmed unless the evidence,
lacking substantial conflict, compels the conclusion that the
motion should have been granted].) As noted, there was no need
to exclude Dr. Wilson’s testimony that the MRI results did not
show nerve compression, on which the jury could have relied to
discredit Dr. Chen’s recommendation for surgery. Additionally,
(Fn. is continued on the next page.)




                                       32
      Finding the error prejudicial, we reverse the judgment
on the verdict and remand for a new trial on all issues. We
deny appellant’s request to limit retrial to the amount of
damages due to the centrality of the causation issue to the
parties’ disputes concerning both liability and damages.
(See Liodas v. Sahadi (1977) 19 Cal.3d 278, 285-286
(Liodas).) Depending upon the parties’ actions on remand,
the County may have the opportunity to permissibly
introduce Dr. Wilson’s contrary opinions -- or similar
opinions from another expert -- at retrial. (See Hirano v.
Hirano (2007) 158 Cal.App.4th 1, 5, 8 [trial court
prejudicially erred in barring party from calling expert

the County effectively impeached Dr. Chen’s causation opinions
by eliciting concessions about the limitations of the information
upon which Dr. Chen relied. For instance, Dr. Chen admitted
that he knew no details about the 2016 accident; that the only
MRI results were obtained after the 2016 accident; that MRI
results are essential to assessing disc injuries; and that the MRI
results suggested that one of the indications for surgery had
developed recently. Appellant himself testified he was injured in
the 2016 accident and contradicted his own descriptions of how
his body struck the interior of the bus during the 2013 accident.
Moreover, Tam billed appellant no more than $2,070, and
Dr. Chen’s testimony that “around $12,000 sound[ed] accurate”
was vague, unsupported by documentary evidence, and unaccom-
panied by any testimony or other evidence establishing that his
bills reflected the reasonable value of his services. (See
Bermudez v. Ciolek (2015) 237 Cal.App.4th 1311, 1330 [“[T]he
measure of medical damages is the lesser of (1) the amount paid
or incurred, and (2) the reasonable value of the medical services
provided”].)




                                33
witnesses at retrial on the basis of that party’s failure to
timely exchange expert witness information before former
trial, where neither party served new demand for expert
exchange after reversal of former judgment]; see also id. at
p. 9 [“[F]ollowing reversal of a prior judgment, . . . the
parties are entitled to change expert witnesses . . . [or to]
elect to use an expert when they had not done so before”].)

      B. Additional Contentions of Error at Trial
      To assist the parties and the court, we address other
alleged errors regarding issues likely to arise on retrial. (See
Liodas, supra, 19 Cal.3d at p. 286; Code Civ. Proc., § 43.) We
find no merit in appellant’s contention that the County’s
counsel misstated the law by arguing that appellant had the
burden to prove that the 2013 accident caused the injuries
                                 14
for which he claimed damages. Counsel permissibly
highlighted appellant’s burden, as the plaintiff, to prove the
County’s negligence caused his injuries, without denying a
defendant’s burden, after the plaintiff has proved his
negligence to be one cause among others, to limit his liability
for damages by proving the apportionment of fault among
multiple causes. (See Espinosa v. Little Co. of Mary Hospital
(1995) 31 Cal.App.4th 1304, 1316, 1322 [trial court, in
14
       Because there is no reason to expect the County’s counsel to
again refer, at retrial, to $1,200 or $1,020 in expenses for
Dr. Chen’s treatment, we decline to address appellant’s
contention that these references were prejudicial misstatements
of the record.




                                34
erroneously granting nonsuit to defendants whom the
plaintiff had proved responsible for two of three concurrent
causes of his indivisible injury, “confused the issue of
damage apportionment, which was not plaintiffs’ burden,
with the requirement which plaintiff did successfully satisfy,
which was to provide evidence that defendants’ negligence,
to a reasonable medical probability, was a cause of plaintiff’s
damage”].) In any event, appellant cannot show prejudice
because he neither alleges error in the jury instructions
explaining the burdens of proof nor rebuts the presumption
that the jury followed them. (See Cassim v. Allstate Ins. Co.
(2004) 33 Cal.4th 780, 803-804 [recognizing presumption].)
Indeed, his own counsel reminded the jury of the
instructions after the alleged misstatement of law.
      Nor do we find error in the admission of evidence
concerning the 2010 accident. The County produced
sufficient evidence identifying appellant as the victim of the
2010 accident to establish the accident’s relevance as
impeachment of appellant’s testimony that he had reported
his complete medical history to Dr. Chen and Tam.
Contrary to appellant’s contention, the County’s failure to
identify Officer Mesun in response to form interrogatory No.
16.1 did not require exclusion of his testimony, given that
appellant identified no applicable court order and no
evidence that the County’s failure was willful. (Mitchell v.
Superior Court (2015) 243 Cal.App.4th 269, 272 [“[E]xclusion
of a party’s witness for that party’s failure to identify the
witness in discovery is appropriate only if the omission was




                              35
willful or a violation of a court order compelling a
response”].)
///
///
///




                               36
                           DISPOSITION
      We reverse the judgment on the verdict and remand for
a new trial on all issues, with instructions to the trial court
to vacate its order on the parties’ post-trial motions and the
judgment entered thereon. Appellant is awarded his costs
on appeal from the judgment on the verdict. To the extent
the parties incurred segregable costs on appellant’s appeal
from the order on the parties’ post-trial motions, they shall
bear their own costs.
               CERTIFIED FOR PUBLICATION




                                        MANELLA, P. J.

We concur:




COLLINS, J.




CURREY, J.




                              37
