                           In the
 United States Court of Appeals
              For the Seventh Circuit
                        ____________

No. 06-2927
DENISE C. CHLOPEK and
JARON M. CHLOPEK,
                                        Plaintiffs-Appellants,
                              v.

FEDERAL INSURANCE COMPANY
and BREG, INCORPORATED,
                                        Defendants-Appellees.
                        ____________
            Appeal from the United States District
          Court for the Western District of Wisconsin.
           No. 05-C-545-S—John C. Shabaz, Judge.
                        ____________
  ARGUED FEBRUARY 23, 2007—DECIDED AUGUST 28, 2007
                   ____________


 Before POSNER, KANNE, and ROVNER, Circuit Judges.
  ROVNER, Circuit Judge. Denise and Jaron Chlopek
sued Breg, Incorporated, the manufacturer of the Polar
Care 300, a device that delivers cooling therapy to post-
operative patients. After nearly ten days of continuous
use of the device on her right foot, Denise experienced
decreased blood flow and tissue damage in her right big
toe. The Chlopeks alleged that the Polar Care 300 was
defective because it contained no warning about the
dangers of continuous use. However, a jury found that the
device was not defective. The Chlopeks appeal, arguing
that the district court erroneously denied their motion
2                                              No. 06-2927

for a new trial. They assert that errors relating to eviden-
tiary matters, the jury instructions, and the district
judge’s conduct rendered their trial unfair. Having deter-
mined that none of the alleged errors resulted in an unfair
trial, we affirm the judgment of the district court.


                            I.
  After undergoing several surgeries on her right big toe
in the late 1980s, Denise Chlopek functioned well for more
than a decade. She was mobile, experienced minimal pain,
and was able to work as a nurse. But in early 2002, she
suddenly began to experience severe pain in her right
foot, and she sought treatment from Dr. Andrew Pankratz,
a podiatrist at the Marshfield Clinic in Eau Claire, Wis-
consin. Dr. Pankratz determined that the artificial joint
that had been implanted in Chlopek’s toe in 1989 had
fractured and failed. Chlopek’s toe was significantly
deformed. After discussing two treatment options with
Dr. Pankratz, Chlopek elected to have “fusion surgery,”
wherein a bone fragment from her hip would be implanted
in her big toe to improve stability and weight-bearing
capability.
  Chlopek underwent surgery at the Eau Claire Surgical
Center on May 31, 2002. Dr. Pankratz, along with an
orthopedic surgeon, performed the surgery, which was
uneventful. After the procedure, Dr. Pankratz prescribed
cold therapy for Chlopek to prevent swelling and treat
pain. Toward that end, he prescribed a Polar Care
300, which he applied to Chlopek’s foot himself after
wrapping the foot in several layers of bandages.
  The Polar Care 300, manufactured by Breg, is a device
consisting of a cooler attached by a tube to a pad that
is wrapped around the patient’s affected area. A pump,
powered by electricity, circulates ice water from the cooler
No. 06-2927                                             3

through the tube and into the pad, allowing for more cold
water to cycle into the pad as heat from the body warms
it. Breg markets the Polar Care as “continuous cooling
therapy.” The device is a Class II medical device, which,
for purposes of this case, means that the Food and Drug
Administration must initially approve the device for its
intended use and thereafter the manufacturer must report
complaints about the device to the agency. The Polar
Care 300 is not marketed to the public; rather, Breg sells
the devices to medical professionals who in turn prescribe
it to their patients. In 2002, the Polar Care 300 had a
warning label affixed to its side with the following ad-
monitions:
   Caution: Federal law restricts this device for sale by
   or on the order of a licensed health care practitioner.
   Warning: Carefully read use instructions and warn-
   ings before operation.
   Warning: Always apply a dressing or other moisture
   barrier between the pad and the patient’s skin.
   Warning: A licensed health care practitioner must
   consider each patient’s sensitivity to cold. A periodic
   inspection of the patient’s skin under the pad is
   recommended. If a noticeable change in skin appear-
   ance in the area of the cold application is observed
   such as burning, itching, blistering, discoloration, or
   increased swelling more than an hour after use,
   discontinue use of this product and consult physician
   immediately. Always apply a barrier or dressing
   between the pad and the patient’s skin. Caution
   should be taken during prolonged use, for children,
   diabetics, incapacitated patients, and those with
   decreased skin sensitivity or poor circulation.
   Warning: Carefully read use instructions and warn-
   ings provided with the water circulating pad that is to
   be used with this pump.
4                                                No. 06-2927

  Chlopek was discharged on May 31, the day of her
surgery. Dr. Pankratz did not give her any directions
with respect to the proper use of the Polar Care 300
and admittedly did not read the warnings on the unit.
However, before Chlopek left the clinic, a discharge nurse
gave her written instructions to keep her foot elevated,
leave the bandage in place at all times, and continue
using the cold therapy for two weeks.1 Chlopek was due
back at the clinic for a follow-up appointment on July 19.
  Chlopek followed the instructions that the dis-
charge nurse gave her, but she did not read the warning
label on the Polar Care 300. Her husband did read the
label, and, concluding the warnings were not inconsistent
with the discharge instructions, continued to follow the
nurse’s instructions. Accordingly, Chlopek used the Polar
Care device continuously, removing the cooling pad only
when she went to the bathroom. After nine days, she
noticed that her baby toe—which, according to Chlopek,
was then visible only because the dressing applied by
Dr. Pankratz had shifted—was purple. (Dr. Pankratz
maintains that the tips of Chlopek’s toes were always
visible.) She returned to the clinic the next day.
  According to Chlopek, when Dr. Pankratz removed the
bandage on her foot, he exclaimed, “This looks like frost-
bite!”. Dr. Pankratz instructed Chlopek to discontinue use
of the Polar Care 300, but he advised her to apply ice
behind her knee three times per day. His treatment notes
for the day of his visit do not say anything about frostbite


1
   Chlopek’s discharge form had the following “special instruc-
tions”: “Quiet activity today. No driving x 24h. Eat light to-
day. Resume home meds, diet and activity. Keep foot/leg ele-
vated x 72h. ICE WRAP x 2 weeks.” The “dressing instructions”
state: “Leave dressing on til see Dr. Leave ice pack on til see
Dr. Keep dressing/cast dry w/ shower.”
No. 06-2927                                                  5

or thermal injury, but he noted blistering and “grayish
discoloration” characteristic of ischemia (decreased blood
flow) on Chlopek’s toes. Over the next month, Chlopek
returned to the clinic for a series of follow-up appoint-
ments. The damaged tissue in Chlopek’s toe was beyond
repair, and so Dr. Pankratz waited until a clear demarca-
tion became evident between the damaged and healthy
tissue. At that point, on July 18, he amputated the dam-
aged tissue, which amounted to Chlopek’s entire right
big toe.
  After the amputation, the Chlopeks sued Breg and its
insurer in the Circuit Court of Eau Claire County, Wiscon-
sin. They alleged that the Polar Care 300 was defective
because its warning label did not caution consumers
that continuous use could lead to thermal injuries. After
service the defendants removed the case to federal dis-
trict court. The Chlopeks survived Breg’s motion for
summary judgment, and a jury trial was scheduled. Over
the plaintiffs’ objection, the district court decided to
bifurcate the trial; only if the jury found during the first
phase that Breg’s product was defective would a trial on
the Chlopeks’ damages be held.
  Before trial, the district court resolved a number of
evidentiary motions. As relevant here, the court granted
in large part the defendants’ motion to exclude evi-
dence—in the form of Breg’s records of customer com-
plaints—of other thermal injuries potentially caused by
the Polar Care 300 and its sister unit, the Polar Care 500.2
The court admitted one of ten incident reports related to


2
  The Polar Care 500 preceded the 300 on the market. It is a
larger unit that is designed to deliver both short-term and
continuous cooling therapy. Unlike the smaller unit, the Polar
Care 500 allows the patient to control and monitor the tempera-
ture in the cooling pad.
6                                               No. 06-2927

the Polar Care 300 upon concluding that the incident
occurred under “substantially similar” circumstances to
those leading to Chlopek’s injury; the court further decided
that admitting evidence involving the Polar Care 500
would waste time and confuse the issues. The district
court also excluded evidence that Breg changed the
warnings on the Polar Care 300 sometime after Chlopek’s
injury; it determined that the evidence was barred under
Federal Rule of Evidence 407 as a later remedial measure.
  Jury selection began on April 24, 2006. During voir dire,
the court asked the potential jurors a number of standard
questions relating to their knowledge of the parties, the
attorneys, and the facts of the case, and their participation
in lawsuits in the past as parties or witnesses. The court
inquired generally about the potential jurors’ attitudes
toward “the commencement of lawsuits, the administra-
tion of justice generally, or jury awards,” but the court did
not did not ask whether the potential jurors had strong
opinions about tort reform or civil damages. After complet-
ing its voir dire, the district court asked the parties if
they had additional questions for the potential jurors. The
court made a few additional inquiries at the defendants’
behest, and then the parties exercised their challenges. A
seven-member jury was empaneled.
  The two-day trial began with the testimony of Denise
and Jaron Chlopek. The plaintiffs also called Lee Sapetti,
a mechanical engineer who testified about the design of
the Polar Care 300 and opined that the product lacked an
adequate warning about potential hazards from continuous
use. Finally, Dr. Pankratz testified for the plaintiffs,
opining that the continuous use of the Polar Care 300 was
one of three possible causes of Chlopek’s injury (the others
being existing vascular damage from prior surgeries and
decreased blood flow caused by cigarette smoking). Among
Breg’s witnesses were two experts. The first, an engineer
with expertise in thermal science, testified that the Polar
No. 06-2927                                              7

Care 300 cannot create skin temperatures cold enough to
cause frostbite. The second was Dr. Lance Silverman, an
orthopedic surgeon, who opined that the use of the Polar
Care 300 was not a cause of the ischemia that led to the
amputation of Chlopek’s toe. At one point during the cross-
examination of Dr. Silverman, the plaintiff ’s attorney,
Drew Ryberg, grew frustrated with the witness for giving
answers when no question had been asked, or for giving
unresponsive answers to counsel’s questions. As Dr.
Silverman responded to a yes-or-no question with a
narrative, Ryberg interjected: “Excuse me, Doctor. This
is done in a question-and-answer format and please deal
with the questions I ask as we proceed.” In response, the
district judge chastised Ryberg and instructed the jury
to disregard his comments:
   Please do not argue to the jury. I wish you would
   disregard counsel’s continual testifying and arguing
   to the jury. There is a simple procedure which you
   haven’t learned yet. When an answer comes in that’s
   nonresponsive, you object thereafter. That’s the gen-
   tlemanly way to do it, that’s the ethical way to do
   it, and that’s the way to do it before this jury.
Ryberg returned to his cross-examination without object-
ing or asking for a sidebar to protest the judge’s remarks.
  At the close of evidence, Breg moved for judgment as a
matter of law, and the district court denied the motion.
The judge instructed the jury and sent them to deliberate
with a special verdict form. The form, which was used over
the plaintiffs’ objection, first asked the jury to decide
whether the Polar Care 300 was defective. If the jury
answered the question in the negative, it was to proceed
no further. If it concluded that the Polar Care 300 was
defective, it was to go on to determine whether the defect
was a cause of Chlopek’s injury. Again, if the jurors
answered yes, they were to proceed to a series of questions
8                                               No. 06-2927

related to the issue of comparative fault on the part of
Chlopek, her husband, Dr. Pankratz, and the Marshfield
Clinic.
  The jury found at the first step that the Polar Care 300
was not defective and did not answer the remaining
questions. On the basis of the special verdict, the district
court entered judgment for the defendants. Shortly
thereafter the Chlopeks filed a motion for a new trial. See
Fed. R. Civ. P. 59(e). They argued that the trial was
unfair for several reasons. First, they asserted that
they had been prejudiced by the bifurcation of the trial and
the district court’s failure to explain the procedure to the
jury. Second, they challenged the court’s exclusion of
evidence of other accidents and of the changes to the
Polar Care 300’s warning label. Third, they argued that
they had been prejudiced by the judge’s rebuke of attorney
Ryberg during the cross-examination of Dr. Silverman.
Finally, they maintained that the special verdict form
confused the issues in the case and unfairly invited the
jury to answer the first question in the negative and “go
home early.” The district court, unpersuaded by any of
the arguments, denied the motion.


                            II.
  On appeal the Chlopeks renew most of the arguments
they made in their motion for a new trial, although they
address them in a rather cursory manner. We review the
denial of the motion for a new trial for abuse of discretion.
See Naeem v. McKesson Drug Co., 444 F.3d 593, 605 (7th
Cir. 2006). We note that, although the substance of this
case was governed by Wisconsin law, the issues the
Chlopeks have raised on appeal are all evidentiary or
procedural, and we therefore apply federal law. See
Schindler v. Seidler, 474 F.3d 1008, 1010 (7th Cir. 2007);
Bevolo v. Carter, 447 F.3d 979, 982 (7th Cir. 2006).
No. 06-2927                                               9

  The Chlopeks first argue that the district court com-
mitted reversible error when it excluded most of their
proffered evidence of other injuries involving the Polar
Care 300 and all the evidence they sought to introduce of
injuries involving the Polar Care 500. In a products-
liability case, evidence of other accidents is relevant to
show the existence of a danger, the defendant’s notice of
the danger, and the cause of the accident. Weir v. Crown
Equip. Corp., 217 F.3d 453, 457 (7th Cir. 2000) (citing
Nachtsheim v. Beech Aircraft Corp., 847 F.2d 1261, 1268
(7th Cir. 1988)). However, before the evidence will be
admitted, the proponent must show that the other acci-
dents occurred under substantially similar circumstances.
Id. As we explained in Nachtsheim, this showing is
necessary because the probative force of evidence of
other accidents decreases “[a]s the circumstances and
conditions of the other accidents become less similar to the
accident under consideration.” Nachtsheim, 847 F.2d at
1268. At the same time, the risk of unfair prejudice
remains, along with potential costs in terms of time and
distraction. Id.
  The district court did not abuse its discretion by exclud-
ing the evidence. First, we note that the court held a
hearing at which it individually considered each accident
report relating to the Polar Care 300 that the plaintiffs
sought to admit. These ten reports, comprising Exhibit 10,
depicted complaints of redness, blistering, “burns,” “nerve
damage,” “frostbite,” and other symptoms, on the
patients’ knees, feet, or legs. The district court admitted
Exhibit 10-C, the report of an injury under circumstances
the court deemed most similar to Chlopek’s: a complaint
of frostbite on the foot and ankle area after the patient
used the Polar Care 300 continuously after surgery. The
remaining incidents, the court determined, were not
similar enough, either because the injury was to another
body part, the type of injury was unclear or not of the
10                                              No. 06-2927

same nature as Chlopek’s, or the nature of the complaint
was different (for example, some consumers simply com-
plained of the absence of temperature control). The
Chlopeks do not address the reports individually; they
simply state that the district court “incorrectly determined
that [the other accidents] were not a of a similar kind” and
that Exhibit 10 “should have been admitted in its en-
tirety.” Such a cursory argument cannot support a re-
versal of the district court’s decision, particularly where
the court discussed each report separately and gave sound
reasons for distinguishing the other incidents from the
one at issue. Moreover, we note that the plaintiffs’ theory
of the case was failure-to-warn, but no information was
supplied about the warnings given in the other cases;
a crucial point of comparison was lacking. See Weir, 217
F.3d at 458.
  As for Exhibit 11, the plaintiffs do not seriously chal-
lenge the exclusion of the accident reports related to the
Polar Care 500; they do not explain why any of the re-
ported incidents was substantially similar nor do they
respond to the district court’s reasons for exclusion. They
state only that the Polar Care 500 was equally capable of
producing frostbite and was comparable for purposes of
the trial. In fact, the district court agreed that the Polar
Care 500 was in many respects similar to the Polar Care
300 but determined nevertheless that it was inadvisable
to “try the 500” when the issue of the case was the ade-
quacy of the warnings on the Polar Care 300. We see no
abuse of discretion in the district court’s determination. As
the court suggested, exploring injuries potentially caused
by the Polar Care 500 could have confused the jury and
unnecessarily prolonged the trial. See Fed. R. Evid. 403;
Guy v. Crown Equip. Corp., 394 F.3d 320, 329 (5th Cir.
2004).
  The final evidentiary decision the plaintiffs challenge
is the exclusion of evidence that Breg changed the warn-
No. 06-2927                                              11

ing label on the Polar Care 300 some time after Chlopek’s
injury; the new label cautions against continuous use for
more than 12 hours. They seek to sidestep Federal Rule of
Evidence 407 by insisting that the change was not a
subsequent “remedial” measure because, according to the
affidavit of a Breg executive, the change was not prompted
by safety concerns. But Breg’s motive for making the
change is irrelevant. All the rule requires is that the
measure “would have made the injury or harm less likely
to occur.” Fed. R. Evid. 407. Regardless of Breg’s stated
reason for the change, the plaintiffs undoubtedly wanted
the jury to conclude that Breg added the warning be-
cause the product was unsafe without it. That is precisely
the type of inference that Rule 407 forecloses, in order to
avoid discouraging the taking of remedial measures. See
Pastor v. State Farm Mut. Auto. Ins. Co., 487 F.3d 1042,
1045 (7th Cir. 2007); Lust v. Sealy, Inc., 383 F.3d 580, 585
(7th Cir. 2004).
  The plaintiffs get no further by arguing that the evid-
ence of the changed warning nevertheless was admissible
because it was relevant to causation. The fact of a new
warning does not tend to prove that the absence of an
adequate warning caused Denise Chlopek’s injury; rather,
it is relevant to whether continuous use of the product
can cause injury. However, Breg never argued that its
product could not cause an injury like Chlopek’s; its
position was that with proper use (including heeding the
existing warnings) on appropriate candidates the product
was safe. In any event, the district court found that
evidence of a changed warning label was excludable for
the additional reason that it would be unfairly prejudicial,
see Fed. R. Evid. 403, and this determination was not an
abuse of discretion.
  Next the plaintiffs challenge the bifurcation of the trial
and, relatedly, the omission of an instruction to help the
jury “delineate the role of the two trials.” Under Federal
12                                             No. 06-2927

Rule of Civil Procedure 42(b), a district judge may separate
claims or issues for trial if the separation would prevent
prejudice to a party or promote judicial economy. See
Houseman v. U.S. Aviation Underwriters, 171 F.3d 1117,
1121 (7th Cir. 1999). If one of these criteria is met, the
district court may order bifurcation as long as doing so
will not prejudice the non-moving party or violate the
Seventh Amendment. Krocka v. City of Chi., 203 F.3d 507,
516 (7th Cir. 2000); Houseman, 1117 F.3d at 1121. The
Chlopeks do not dispute that bifurcation served the
interest of judicial economy and did not result in a viola-
tion of the Seventh Amendment, and so the only issue
is prejudice.
   The Chlopeks contend that the bifurcation prevented
them from presenting evidence that was “mixed in charac-
ter,” namely, evidence “that other aspects of tissue below
the knee were affected.” But, contrary to the Chlopeks’
assertion, evidence about the full extent of Denise’s
injuries was not relevant to the only fact at issue in the
first phase of trial: whether the Polar Care 300 was
defective because of inadequate warnings. See Krocka, 203
F.3d at 516; Hydrite Chem. Co. v. Calumet Lubricants Co.,
47 F.3d 887, 890-91 (7th Cir. 1995) (explaining that in
bifurcated proceedings, “the fact of injury belongs in the
first trial and the quantification of the injury by means
of an assessment of damages in the second”). As the
district court noted when denying the Chlopeks’ motion for
a new trial, the jury was well aware that Denise suffered
injuries to her toe resulting in its amputation. An in-depth
presentation about the full extent of her injuries was
best left for the damages phase so as not to cloud the
issues or prejudice the defendant. And the plaintiffs’
contention that bifurcation results in a proceeding that is
“too expensive” is a non-starter; they were not financially
prejudiced by a second phase of trial that never occurred.
  As for the contention that the district court erroneously
failed to instruct the jury on the issue of bifurcation, we
No. 06-2927                                                13

note that the plaintiffs argue from the faulty premise that
Rule 42(b) requires the district court to instruct the jury
about bifurcation. The jury instructions in this case
appropriately focused on the issue of liability and omitted
any mention of damages; the instructions were there-
fore sufficient to ensure that the jury during the liability
phase knew its role. In any case, the plaintiffs did not
propose an instruction on bifurcation, and so they are not
entitled to any relief. See Penn v. Harris, 296 F.3d 573, 577
(7th Cir. 2002).
  The plaintiffs present as a related error the district
court’s use of a special verdict form that, they say, dis-
torted the issues and contained “random inquiries” that
prejudiced their case. According to the Chlopeks there
was “no evidence” presented at trial regarding the negli-
gence of Jaron Chlopek, Dr. Pankratz, or the Marshfield
Clinic, and so the special verdict form should not have
mentioned them. The Chlopeks also take issue with the
format of the document, which, they assert, invited the
jury “to end work early.” The plaintiffs refer to the in-
struction to proceed no further if the jury answered “no” to
the question of whether the Polar Care 300 was defective.
  The formulation of special verdict questions is a matter
of the trial court’s discretion. Fed. R. Civ. P. 49(a); Mattson
v. Schultz, 145 F.3d 937, 939 (7th Cir. 1998). However, the
verdict from must “accurately, adequately, and clearly
state the relevant issues,” and “[a]mbiguous, biased,
misleading, or confusing questions may warrant reversal.”
Mattson, 145 F.3d at 939. Here, the special verdict
form first asked the jury to decide if the Polar Care 300
was “in a defective condition so as to be unreasonably
dangerous to a prospective user.” An answer of “no” would
end deliberations, while an affirmative response would
lead the jury to decide whether the defect was a cause of
Denise Chlopek’s injury. Only after answering “yes” to
the first two questions would the jury then confront
14                                               No. 06-2927

issues of comparative fault. The district court’s formula-
tion of the questions did not exceed the bounds of its
discretion. Although the first question could have pre-
sented the plaintiffs’ theory of the case more specifically by
linking the defective condition to the absence of adequate
warnings, the jury instructions covered that ground. By
inquiring first into the condition of the Polar Care 300 and
second into whether the product caused Denise Chlopek’s
injury, the special verdict form focused the jury on the
plaintiff ’s theory, and so the questions “accurately,
adequately, and clearly” stated the main issue of the case.
  The plaintiffs’ argument that the verdict form improp-
erly invited the jury to answer the first question in the
negative and “go home early” is confusing. Surely they do
not mean to contend that the jury should have gone on to
answer questions related to causation and comparative
fault after deciding that the Polar Care 300 was not
defective. And, contrary to the plaintiff ’s assertion that “no
evidence” was presented regarding the negligence of any
parties with the possible exception of Denise Chlopek, the
jury reasonably could have inferred from the testimony at
trial that the negligence of third parties caused or contrib-
uted to Chlopek’s injuries. The inquiries, therefore, were
not confusing and “random” as the plaintiffs contend, and
the mere presence of these questions did not prejudice
them. The plaintiffs point to no evidence to overcome the
strong presumption that juries follow instructions, see 3M
v. Pribyl, 259 F.3d 587, 600 (7th Cir. 2001), and we will
not conclude that the jury approached the verdict form out
of order, or with an eye towards an early dismissal, based
solely on the plaintiffs’ speculation.
  The Chlopeks next challenge the district court’s failure
to specifically inquire during voir dire about the potential
jurors’ “perceptions . . . regarding the propriety” of civil
damages cases, “particularly in light of the assault on the
civil jury system conducted by many politicians throughout
No. 06-2927                                               15

America.” The plaintiffs do not cite any authority for
the proposition that a judge must investigate potential
jurors’ view on tort reform. Indeed we have rejected this
very argument, as have other courts. See Alcala v. Emhart
Induss., Inc., No. 06-3153, 2007 WL 1958640, at *2 (7th
Cir. July 5, 2007); Smith v. Tenet Healthsystem SL, Inc.,
436 F.3d 879, 884 (8th Cir. 2006); Smith v. Vicorp, Inc.,
107 F.3d 816, 818 (10th Cir. 1997). The trial court has
broad discretion over the selection of questions to potential
jury members, and the parties have no right to have a
particular question posed. See Gardner v. Barnett, 199
F.3d 915, 920-21 (7th Cir. 1999). The parties may re-
quest that the court explore certain biases, but the court
is under no obligation to root them out sua sponte—with
certain exceptions not relevant here. See United States v.
Montenegro, 231 F.3d 389, 394 (7th Cir. 2000). In this case,
the district court asked generally if any potential juror had
an opinion about “the commencement of lawsuits, the
administration of justice generally, or jury awards which
would in any way affect your respective abilities to serve
as a fair an impartial juror in this case.” Receiving no
affirmative responses, the judge did not inquire further.
The questions that the plaintiffs proposed before trial
were only slightly more specific than the judge’s on the
subject of tort reform, and the court’s failure to formulate
more detailed questions on its own was hardly an abuse
of discretion.
  Next the plaintiffs argue that they were prejudiced by
the district judge’s criticism—in the presence of the
jury—of attorney Ryberg’s cross examination of Breg’s
expert, Dr. Silverman. They contend that by suggesting
that Ryberg was not handling the witness’s unresponsive-
ness in an “ethical” or “gentlemanly” way, the judge
irreparably damaged the plaintiffs’ case. We rarely will
reverse a judgment because of the district court’s conduct
at trial. See Cooper v. Casey, 97 F.3d 914, 918 (7th Cir.
16                                              No. 06-2927

1996). The rules of evidence give a district judge wide
latitude to control proceedings so as to “(1) make the
interrogation and presentation effective for the ascer-
tainment of the truth, (2) avoid needless consumption of
time, and (3) protect witnesses from harassment or undue
embarrassment.” Fed. R. Evid. 611(a); see United States v.
Reynolds, 189 F.3d 521, 529 (7th Cir. 1999). Generally
speaking, a judge should be impartial and should reserve
criticism for times when the jury is not present, United
States v. Mohammad, 53 F.3d 1426, 1434 (7th Cir. 1995),
but reversible error occurs “only when the judge so im-
pairs the lawyer’s credibility in the eyes of the jury as to
deprive the client of a fair trial,” Cooper, 97 F.3d at 919.
  We are not persuaded that the one instance of judicial
intemperance the plaintiffs cite evinced bias or resulted
in prejudice. Although the judge’s comment perhaps was
itself unfortunate, it was hardly the “lacerating critique”
or the “attack” the plaintiffs label it. The court’s underly-
ing point—that attorney Ryberg should have moved to
strike Dr. Silverman’s unresponsive answer rather than
chastise the witness in front of the jury—is well-taken,
although the suggestion that Ryberg’s conduct was not
“ethical” was regrettable. More importantly, the primary
setback that the plaintiffs identify is not borne out by
the record. The Chlopeks assert that counsel was pre-
vented from pursuing questions designed to bring to light
Dr. Silverman’s “bias.” Having reviewed the transcript,
however, we are convinced that counsel adduced that
Dr. Silverman charged exorbitant fees to render his
opinion that the Polar Care 300 did not cause Chlopek’s
injury. The judge’s scolding did not obscure this point—
indeed, counsel had already moved on. We also note that
counsel quite eloquently asked the jury during his closing
argument to focus on the substance and not the form of
his questioning of Dr. Silverman. This statement, com-
bined with a jury instruction admonishing the jurors not
No. 06-2927                                           17

to take any of the judge’s statements as a signal of his
opinion on the merits of either party’s case, reduced the
possibility of prejudice. See Reynolds, 189 F.3d at 529.
Although the judge’s response to counsel’s misstep could
have been more measured, it did not result in prejudice.
See Mohammed, 53 F.3d at 1434.


                           III.
  The Chlopeks have not identified any errors that neces-
sitate a new trial. Accordingly, we affirm the judgment
of the district court.

A true Copy:
      Teste:

                      ________________________________
                      Clerk of the United States Court of
                        Appeals for the Seventh Circuit




                  USCA-02-C-0072—8-28-07
