                       Nebraska Advance Sheets
	                MID AMERICA AGRI PRODUCTS v. ROWLANDS	305
	                           Cite as 286 Neb. 305

                       VI. CONCLUSION
   We find no abuse of discretion by the district court in its
procedures for determining the admissibility of evidence of
Valverde’s prior sexual assaults. Because Valverde moved for
a mistrial before any evidence of the prior sexual assaults had
been adduced, the district court did not abuse its discretion in
overruling the motion. Finally, we find no reversible error by
the court in the jury instructions that it gave or in the rejection
of Valverde’s proposed instructions. Accordingly, we affirm
the judgment of the district court.
                                                       Affirmed.



        Mid America Agri P roducts/Horizon, LLC, et al.,
         relators, v. Honorable Donald E. Rowlands,
           Judge, District Court for Lincoln County,
            Nebraska, respondent, and Lansing Trade
               Group, LLC, and Lansing Ethanol
                   Services, LLC, intervenors.
                                    ___ N.W.2d ___

                         Filed July 19, 2013.     No. S-12-473.

 1.	 Mandamus. A court issues a writ of mandamus only when (1) the relator has
      a clear right to the relief sought, (2) a corresponding clear duty exists for the
      respondent to perform the act, and (3) no other plain and adequate remedy is
      available in the ordinary course of law.
 2.	 Mandamus: Proof. In a mandamus action, the party seeking mandamus has the
      burden of proof and must show clearly and conclusively that such party is entitled
      to the particular thing the relator asks and that the respondent is legally obligated
      to act.
 3.	 Verdicts: Evidence: Appeal and Error. Recommended factual findings of a
      special master have the effect of a special verdict, and the report upon questions
      of fact, like the verdict of a jury, will not be set aside unless clearly against the
      weight of the evidence.
 4.	 Mandamus: Words and Phrases. A writ of mandamus is issued to compel the
      performance of a purely ministerial act or duty, imposed by law upon an inferior
      tribunal, corporation, board, or person.
  5.	 ____: ____. Mandamus is a law action and is an extraordinary remedy, not a writ
      of right.
    Nebraska Advance Sheets
306	286 NEBRASKA REPORTS


 6.	 Attorneys at Law: Expert Witnesses. The central concern in cases in which
     counsel has retained a side-switching expert is whether counsel has unfairly
     obtained confidential information about the opposing party.

   Original action. Writ of mandamus denied.
   George E. Clough, of Clough Law Office, and Paul H.
Schwartz, of Shoemaker, Ghiselli & Schwartz, L.L.C., for
relators.
   Jay C. Elliott, of Elliott Law Office, P.C., L.L.O., Kirk
T. May and Jeremy M. Suhr, of Rouse, Hendricks, German
& May, P.C., and William G. Dittrick and Kenneth W.
Hartman, of Baird Holm, L.L.P., for intervenor Lansing Trade
Group, LLC.
   No appearance for respondent.
  Heavican, C.J., Wright, Connolly, Stephan, McCormack,
and Cassel, JJ.
   Wright, J.
                     I. NATURE OF CASE
   This action presents the question whether a law firm should
be disqualified for retaining an expert who, prior to being
retained, consulted with opposing counsel on the same matter.
Lansing Trade Group, LLC, and Lansing Ethanol Services,
LLC (collectively Lansing), commenced an action against
Mid America Agri Products/Horizon, LLC, and other defend­
ants (collectively Horizon) over certain “forward corn con-
tracts.” Counsel for Horizon attempted to retain a grain indus-
try expert and conveyed confidential information to him.
Lansing’s counsel later retained the same expert. The dis-
trict court for Lincoln County, Nebraska, the respondent in
this proceeding, sustained Horizon’s motion to disqualify the
expert from testifying but overruled Horizon’s subsequent
motion to disqualify Lansing’s counsel. Horizon filed this
original action seeking a writ of mandamus requiring the dis-
trict court to disqualify Lansing’s counsel. For the following
reasons, we deny the writ.
                  Nebraska Advance Sheets
	           MID AMERICA AGRI PRODUCTS v. ROWLANDS	307
	                      Cite as 286 Neb. 305

                    II. SCOPE OF REVIEW
   [1,2] A court issues a writ of mandamus only when (1) the
relator has a clear right to the relief sought, (2) a correspond-
ing clear duty exists for the respondent to perform the act, and
(3) no other plain and adequate remedy is available in the ordi-
nary course of law. Schropp Indus. v. Washington Cty. Atty.’s
Ofc., 281 Neb. 152, 794 N.W.2d 685 (2011). The party seeking
mandamus has the burden of proof and must show clearly and
conclusively that such party is entitled to the particular thing
the relator asks and that the respondent is legally obligated
to act. Id.
   [3] Recommended factual findings of a special master have
the effect of a special verdict, and the report upon questions
of fact, like the verdict of a jury, will not be set aside unless
clearly against the weight of the evidence. See Larkin v.
Ethicon, Inc., 251 Neb. 169, 556 N.W.2d 44 (1996).
                          III. FACTS
                    1. Communications With
                       Horizon’s Counsel
   Lansing brought an action against Horizon in 2009 relat-
ing to “forward corn contracts.” Lansing is the plaintiff in
the underlying action and the intervenor in the present action.
Horizon is the defendant in the underlying action and the rela-
tor in the present action. In November 2010, James Nesland,
a lead defense attorney for Horizon, contacted Howard J.
O’Neil as a possible expert witness for Horizon. They dis-
cussed the National Grain and Feed Association (NGFA) Grain
Trade Rules.
   According to Nesland, O’Neil said he could serve as a
defense expert despite being well acquainted with Lansing.
Nesland claimed that because of O’Neil’s experience as an
expert and willingness to assist the defense, Nesland “reason-
ably believed that [their] communications were in confidence.”
Once O’Neil agreed to be a defense expert, Nesland shared his
thoughts, opinions, impressions, and ideas concerning the tes-
timony he believed important regarding the NGFA. He specifi-
cally discussed his views about the case.
    Nebraska Advance Sheets
308	286 NEBRASKA REPORTS



   O’Neil claims he did not recall Nesland’s providing him
with proprietary information. Nesland received an e-mail from
O’Neil dated January 6, 2011, stating that O’Neil did not
have time to work on the case. O’Neil recommended another
expert, whom he copied on the e-mail, but he had “‘not shared
any of your [proprietary] information with him.’” Nesland
and O’Neil corresponded about another expert Horizon
might retain.
   After February 2011, Robert Christie, Nesland’s cocoun-
sel, undertook primary responsibility for developing Horizon’s
experts. About 2 months later, Christie contacted O’Neil, and
at that time, O’Neil was available to discuss the case on a con-
fidential basis.
   During their conversation on May 4, 2011, O’Neil informed
Christie that he was not comfortable testifying because of
his long-term relationship with a company named “The
Andersons,” a part owner of Lansing. Christie said that O’Neil
had no objection to confidentially acting as a nontestifying
consultant and opining on NGFA rules and related issues.
Based on assurances from O’Neil that their communications
were confidential, Christie discussed confidential information,
including his opinion on the issues where O’Neil’s expertise
was relevant.
   O’Neil described the conversation as an “exchange of pleas-
antries” and a general discussion of NGFA rules. O’Neil said
he told Christie he could not consult for him against Lansing.
Christie then asked whether O’Neil would be willing to dis-
cuss NGFA rules generally, which he agreed to do. O’Neil
said he did not remember discussing a company named “The
Andersons” and did not believe Christie shared confidential
information and did not consider anything in their conversa-
tion confidential. O’Neil said Christie told him that Lansing’s
position was incorrect and that Lansing had not lived up
to its contracts. O’Neil understood this to mean Horizon
was adverse to Lansing. He did not recall that anyone from
Horizon gave him any other impressions or strategies regard-
ing the case.
   Christie said that a few days later, he and O’Neil exchanged
views and opinions. Christie remembered confirming O’Neil’s
                  Nebraska Advance Sheets
	           MID AMERICA AGRI PRODUCTS v. ROWLANDS	309
	                      Cite as 286 Neb. 305

agreement to keep information confidential. Following this
second conversation, Christie received a $225 invoice from
O’Neil for the May 4, 2011, call. The firm paid the invoice.
This was the only invoice O’Neil sent to Horizon. There was
no written retention agreement between O’Neil and Horizon.

                     2. Communications With
                        Lansing’s Counsel
   In November 2011, Kirk May, an attorney for Lansing,
spoke to O’Neil to determine if O’Neil was a suitable expert
witness. O’Neil believed another lawyer had contacted him
regarding the same case. He did not remember the lawyer’s
name, but “Bob Christie” sounded familiar. O’Neil mentioned
a single conversation several months earlier. May believed that
Christie would not share confidential information with O’Neil
once Christie knew of O’Neil’s connection with Lansing. May
also expected that if Horizon had retained O’Neil, it would
have executed a written retention agreement.
   On November 20, 2011, May sent O’Neil a confirmation of
his retention as a plaintiff’s expert for Lansing. O’Neil con-
firmed his retention and e-mailed Christie on November 26,
saying that he could not assist Horizon in the matter. According
to Christie, O’Neil said he could not be a defense expert for
Horizon because his connections to Lansing would cause a
conflict of interest. However, in an e-mail sent to Christie on
November 30, O’Neil recommended potential experts. May did
not know until April 2012 that O’Neil was providing Horizon
with names of potential experts.
   O’Neil proceeded to work for Lansing and provided an
expert report. On February 16, 2012, Lansing disclosed O’Neil
as an expert witness and provided a copy of O’Neil’s report to
the defense. Christie claimed this was the first time he knew
Lansing had retained O’Neil. The report addressed subject mat-
ter he discussed with O’Neil.
   On February 20, 2012, a lawyer for Horizon sent May
an e-mail stating Horizon’s counsel had shared confidential
information with O’Neil and paid for his services. On the
same day, O’Neil sent May a copy of his November e-mail to
Christie stating he could not be an expert for Horizon. This
    Nebraska Advance Sheets
310	286 NEBRASKA REPORTS



was the first time O’Neil informed May of this exchange
with Christie.
   The next day, O’Neil told May that Christie had not shared
any confidential information with him. O’Neil claimed that no
one acting for Horizon shared defense strategy with him and
that he did not have or share confidential information about the
defense with May or Lansing’s firm.

                    3. Trial Court’s Order
   Horizon moved to disqualify O’Neil as a witness. The court
sustained the motion and disqualified O’Neil from testifying as
an expert witness. On April 6, 2012, Horizon moved to reopen
discovery to explore whether Lansing’s counsel should be dis-
qualified. That motion was overruled. On April 27, Horizon
moved to disqualify Lansing’s counsel, and the court overruled
the motion.
   The trial court found that Horizon had been unable to
advance any evidence that Horizon’s trial strategy, work prod-
uct, or mental impressions had been communicated by O’Neil
to May. It declined to find that May, his firm, and his cocoun-
sel created an appearance of impropriety which would taint the
proceedings. It concluded that the remedy which it had already
imposed upon Lansing, preventing it from calling O’Neil as an
expert witness, was more than sufficient to guarantee Horizon
a fair trial.

                      4. Mandamus Action
   Horizon applied for leave to file an original action for
a writ of mandamus requiring the district court (hereinafter
Respondent) to disqualify Lansing’s counsel. Lansing defended
the action as an intervenor. We granted leave to file an original
action and issued an alternative writ of mandamus requiring
the Respondent to disqualify Lansing’s counsel or show cause
why the writ should not issue.
   We appointed a special master. She concluded that O’Neil
was not a support person as defined by Neb. Ct. R. of Prof.
Cond. § 3-501.9(f). She accepted the finding of the Respondent
that a confidential relationship existed and that confidential
information had been communicated by Horizon to O’Neil,
                  Nebraska Advance Sheets
	           MID AMERICA AGRI PRODUCTS v. ROWLANDS	311
	                      Cite as 286 Neb. 305

but that at no time did O’Neil communicate to Lansing any
of the discussions or communications which O’Neil had with
Horizon’s counsel. The special master found that any presump-
tion of disclosure was rebutted by Lansing and that Lansing’s
counsel’s continued representation did not threaten to taint
further proceedings.
   She concluded that Horizon failed to establish it had a clear
right to the disqualification of Lansing’s counsel and failed
to establish that Respondent was legally obligated to order
disqualification. She also concluded that Respondent did not
abuse its discretion in refusing to disqualify Lansing’s counsel
and that Horizon was not entitled to a writ of mandamus.
               IV. ASSIGNMENT OF ERROR
  Horizon assigns that the trial court erred in overruling its
motion to disqualify Lansing’s counsel.
                         V. ANALYSIS
                          1. Mandamus
                      (a) Legal Principles
   Horizon seeks a writ of mandamus from this court requiring
the Respondent to disqualify Lansing’s counsel because of its
retention of O’Neil as an expert witness. Typically, the denial
of a motion to disqualify will be challenged by mandamus. See
McCully, Inc. v. Baccaro Ranch, 279 Neb. 443, 778 N.W.2d
115 (2010).
   [4,5] The following legal principles apply to an action for
writ of mandamus. A writ of mandamus is issued to compel
the performance of a purely ministerial act or duty, imposed
by law upon an inferior tribunal, corporation, board, or person.
Stetson v. Silverman, 278 Neb. 389, 770 N.W.2d 632 (2009).
Mandamus is a law action and is an extraordinary remedy,
not a writ of right. See id. A court issues a writ of mandamus
only when (1) the relator has a clear right to the relief sought,
(2) a corresponding clear duty exists for the respondent to
perform the act, and (3) no other plain and adequate remedy
is available in the ordinary course of law. Schropp Indus. v.
Washington Cty. Atty.’s Ofc., 281 Neb. 152, 794 N.W.2d 685
(2011). The party seeking mandamus has the burden of proof
    Nebraska Advance Sheets
312	286 NEBRASKA REPORTS



and must show clearly and conclusively that such party is
entitled to the particular thing the relator asks and that the
respondent is legally obligated to act. Id.

                          (b) § 3-501.9
   Attorneys in Nebraska are governed by the Nebraska Rules
of Professional Conduct. Section 3-501.9 is applicable to this
matter and states:
        (a) A lawyer who has formerly represented a client in
     a matter shall not thereafter represent another person in
     the same or a substantially related matter in which that
     person’s interests are materially adverse to the interests of
     the former client . . . .
        ....
        (d) A lawyer shall not knowingly allow a support per-
     son to participate or assist in the representation of a cur-
     rent client in the same or a substantially related matter in
     which another lawyer or firm with which the support per-
     son formerly was associated had previously represented a
     client . . . .
        (e) If a support person, who has worked on a matter, is
     personally prohibited from working on a particular mat-
     ter under Rule 1.9(d), the lawyer or firm with which that
     person is presently associated will not be prohibited from
     representing the current client in that matter if:
        ....
        . . . the support person is screened from any per-
     sonal participation in the matter to avoid communication
     to others in the firm of confidential information that
     both the support person and the firm have a legal duty
     to protect.
        (f) For purposes of Rules 1.9(d) and (e), a support
     person shall mean any person, other than a lawyer, who
     is associated with a lawyer or a law firm and shall
     include but is not necessarily limited to the following: law
     clerks, paralegals, legal assistants, secretaries, messengers
     and other support personnel employed by the law firm.
     Whether one is a support person is to be determined by
                  Nebraska Advance Sheets
	           MID AMERICA AGRI PRODUCTS v. ROWLANDS	313
	                      Cite as 286 Neb. 305

      the status of the person at the time of the participation in
      the representation of the client.
   A brief history of § 3-501.9 sets the background for our
resolution of this matter. Section 3-501.9 developed from a
response to Nebraska case law regarding conflicts of interest
that arise when lawyers move from one firm to another.
   In State ex rel. Freezer Servs., Inc. v. Mullen, 235 Neb.
981, 458 N.W.2d 245 (1990), we disqualified a law firm from
representing a defendant. The attorneys in a firm that had rep-
resented the plaintiff joined the defendant’s firm. We presumed
an attorney leaving one firm acquired client confidences while
at the firm, regardless of whether the attorney was actually
privy to any confidential communications. We also presumed
the attorney shared or would share those confidences with
members of any firm the lawyer subsequently joined. We
held that
      when an attorney who was intimately involved with the
      particular litigation, and who has obtained confidential
      information pertinent to that ligation, terminates the rela-
      tionship and becomes associated with a firm which is
      representing an adverse party in the same litigation, there
      arises an irrebuttable presumption of shared confidences,
      and the entire firm must be disqualified from further
      representation.
Id. at 993, 458 N.W.2d at 253.
   In State ex rel. FirsTier Bank, 244 Neb. 36, 503 N.W.2d
838 (1993), an attorney was employed at a law firm while
that firm worked on a case for a defendant. That attorney, and
several other attorneys from the firm, formed a new firm with
other attorneys. The new firm represented the plaintiffs in an
underlying action. The six attorneys from the first firm who
were still with the second firm at the time of the proceedings in
Buckley testified by affidavit that they received no information
on the underlying action. We adopted a bright-line rule:
      [A]n attorney must avoid the present representation of a
      cause against a client of a law firm with which he or she
      was formerly associated, and which cause involves a sub-
      ject matter which is the same as or substantially related
    Nebraska Advance Sheets
314	286 NEBRASKA REPORTS



      to that handled by the former firm while the present attor-
      ney was associated with that firm.
Id. at 45, 503 N.W.2d at 844.
   The year after Buckley, this court applied the bright-line
rule to a law firm in State ex rel. Creighton Univ. v. Hickman,
245 Neb. 247, 512 N.W.2d 374 (1994). We held that opposing
counsel had to be disqualified after hiring a clerical worker
that, unbeknownst to the firm, had worked on the same case
as an attorney for an adverse party. We concluded that the
hardship worked by this result was outweighed by the need to
maintain the confidentiality of communications and avoid the
appearance of impropriety.
   Following Hickman, the Lawyers’ Advisory Committee
issued Nebraska Ethics Advisory Opinion for Lawyers No.
94-4. The opinion applied the bright-line rule to clerks, para­
legals, secretaries, and other ancillary staff members who
moved from one law firm to another. The opinion specifically
stated that screening was insufficient to avoid disqualification.
The opinion had the practical effect of preventing legal offices
from hiring administrators, paralegals, law clerks, secretar-
ies, and other ancillary personnel who had worked for legal
offices that had or would represent clients adverse to clients
of the hiring office. Due to potential conflicts of interest,
several law firms ceased hiring law clerks from Nebraska law
schools. In response to opinion No. 94-4, the Nebraska State
Bar Association petitioned this court to modify Nebraska’s
Code of Professional Responsibility.
   In 1997, this court adopted Canon 5, DR 5-109, of the
code. DR 5-109 defined a support person as a person other
than a lawyer associated with a lawyer or firm, and expressly
included law clerks, paralegals, legal assistants, secretaries,
and messengers. The rule prohibited a lawyer from knowingly
allowing a support person to assist in the representation of a
client if (1) the support person was associated with a firm that
represented a materially adverse party in the same or a sub-
stantially related matter and (2) the support person acquired
confidential information that was material to the matter.
Support persons were presumed to have acquired confidential
information until they proved otherwise. In September 2005,
                  Nebraska Advance Sheets
	           MID AMERICA AGRI PRODUCTS v. ROWLANDS	315
	                      Cite as 286 Neb. 305

DR 5-109 was replaced by § 3-501.9 when Nebraska’s Code
of Professional Responsibility was replaced by the Nebraska
Rules of Professional Conduct.

                     (c) Parties’ Arguments
   Horizon claims an irrebuttable presumption applies to an
expert who receives confidential information from one party
and then works for an adverse party on a substantially related
matter. It claims that an irrebuttable presumption must apply
to experts because a genuine threat exists that the informa-
tion conveyed by the first party to the expert will benefit the
adverse party. It maintains that even if the information is not
disclosed, the expert cannot ignore it while working for the
adverse party. Horizon argues there is a substantial risk of one
party benefiting from an adverse party’s confidential informa-
tion when an expert is involved, because experts/consultants
work on the “substance” of cases.
   Lansing claims there is nothing in the record or Nebraska
state law supporting the application of an irrebuttable presump-
tion to an expert. It argues that Horizon had no clear right to
disqualification and that Respondent had no clear duty to dis-
qualify Lansing’s counsel.

                         (d) Resolution
   Two questions are presented by this action: Was O’Neil a
support person as defined by § 3-501.9(f) and, if not, should
an irrebuttable presumption that O’Neil conveyed confidential
information to Lansing’s counsel apply? We have not previ-
ously considered whether experts are classified as support
persons or should be subject to the irrebuttable presumption
applied to lawyers. Other jurisdictions have not addressed
issues involving support persons, because § 3-501.9(d) through
(f) are unique to Nebraska. In defining a “support person,”
§ 3-501.9(f) expressly excludes lawyers. Experts are not
expressly addressed by the rule. They are not included as sup-
port persons, nor are they excluded. The person’s classification
as a support person is to be determined by his or her status at
the time of the participation in the representation of the client.
See id.
    Nebraska Advance Sheets
316	286 NEBRASKA REPORTS



   The term “support person” implies a continuing employ-
ment associated with the day-to-day activities of the lawyer or
firm. Support persons are not free to perform similar work for
other lawyers or firms. Included within this category are law
clerks, paralegals, legal assistants, secretaries, messengers,
and other support personnel employed by the law firm. See
§ 3-501.9. Experts, on the other hand, are hired for a particular
issue or problem and therefore do not fit into this category.
They are independent of the control or authority which is
exercised by the firm over its support personnel. Their infor-
mation and expertise is usually sought for litigation requir-
ing an opinion or testimony concerning a specific issue that
requires specialized knowledge or skill. They are similar to
independent contractors that are hired for their knowledge or
skill to be applied to a specific task. They are not employees
of the firm. Since they are hired to testify and give opinions
at trial, they remain independent of the employment by the
firm. A law clerk or paralegal could not be employed by a firm
and also testify as an expert witness for the firm. See, Neb.
Ct. R. of Prof. Cond. § 3-503.7(a) (stating “lawyer shall not
act as advocate at a trial in which the lawyer is likely to be a
necessary witness”); Neb. Ct. R. of Prof. Cond. § 3-505.3(b)
(stating “lawyer having direct supervisory authority over the
nonlawyer shall make reasonable efforts to ensure that the
person’s conduct is compatible with the professional obliga-
tions of the lawyer”). The expert could not be employed by the
firm as a support person and also testify as an expert witness.
The special master concluded that O’Neil was not a support
person, and we agree.
   We next address the presumption that is to be applied to
O’Neil as an expert witness. How the rules of professional
conduct should be applied is a question of law that we review
independent of the conclusions of a respondent and a special
master. See Lamar Co. v. City of Fremont, 278 Neb. 485, 771
N.W.2d 894 (2009). Section 3-501.9 distinguishes between
lawyers and support persons regarding the application of the
presumption of shared confidences.
   Our precedents have applied an irrebuttable presumption
only to persons who obtained confidential information while
                  Nebraska Advance Sheets
	           MID AMERICA AGRI PRODUCTS v. ROWLANDS	317
	                      Cite as 286 Neb. 305

working as lawyers. And for the reasons set forth, we conclude
that an irrebuttable presumption of shared confidences shall
be applied only to actions involving individuals who obtained
confidential information as lawyers.
   In Bechtold v. Gomez, 254 Neb. 282, 576 N.W.2d 185
(1998), a private attorney who was representing a client in a
paternity case hired a law student to do work on a matter not
related to the paternity case. The student previously worked
for a legal clinic under a supervising attorney at a time when
the clinic actively represented an opposing party in the pater-
nity action. The trial court disqualified the clinic’s supervising
attorney. We reversed the disqualification because there was no
evidence that the law student received any confidences from
the private attorney regarding the paternity matter. The student
could not have shared such confidences with the supervising
attorney to warrant disqualifying the supervising attorney. We
refused to apply an irrebuttable presumption of shared confi-
dences to the law student. “In the cases where we have applied
the irrebuttable presumption of shared confidences, the context
has been that of an actual partnership or employment relation-
ship.” Id. at 290, 576 N.W.2d at 191 (collecting cases concern-
ing attorney relationships).
   Other courts have recognized a distinction between lawyers
and experts and have not applied an irrebuttable presumption,
which is described as a per se vicarious disqualification rule,
to a side-switching expert. In North Pacifica, LLC v. City of
Pacifica, 335 F. Supp. 2d 1045 (N.D. Cal. 2004), the court
discussed the substantial differences between the roles played
by experts and counsel. Attorneys have an ethical duty to rep-
resent and advocate for their clients and are bound by a duty
of loyalty. Id. Moreover, the practical realities differ between
a relationship an attorney has with an expert and that which
an attorney has with other attorneys sharing a practice. Id. An
attorney’s disqualification extends to the entire firm, because
when attorneys practice together, they presumptively share
access to privileged and confidential matters. Id. The disquali-
fication rule applied to attorneys “‘recognizes the everyday
reality that attorneys, working together and practicing law in a
professional association, share each other’s, and their client’s,
    Nebraska Advance Sheets
318	286 NEBRASKA REPORTS



confidential information.’” Id. at 1051 (quoting People v.
SpeeDee Oil Change Systems, Inc., 20 Cal. 4th 1135, 980 P.2d
371, 86 Cal. Rptr. 2d 816 (1999)). Vicarious disqualification is
necessary to preserve both the confidentiality of client informa-
tion, as well as public confidence in the legal profession and
the judicial process by enforcing the attorney’s duty of undi-
vided loyalty. Id. See City of Santa Barbara v. Superior Court,
122 Cal. App. 4th 17, 18 Cal. Rptr. 3d 403 (2004).
   That same relationship does not exist in the context of
retained experts. See North Pacifica, LLC, supra. Their role
is limited. Id. They are tasked with providing opinions on spe-
cific matters raised in the litigation. See id. They do not share
the same duty of loyalty to clients. Id. There is no sustained
relationship in a joint enterprise and common access to and
sharing of information as is the case with attorneys sharing a
law practice. Id.
   [6] In North Pacifica, LLC, the plaintiff moved to disqualify
the defendant’s experts and current counsel. Following a hear-
ing, the court disqualified the experts but did not disqualify
the attorneys. The court stated that cases involving vicarious
disqualification of the entire law firm were not applicable
where the disqualified party is an expert and not a member
of the firm. Instead of applying a per se vicarious disquali-
fication rule that is applied to lawyers and law firms, courts
have applied a fact-specific test where experts are concerned.
The central concern in cases in which counsel has retained a
side-switching expert is whether counsel has unfairly obtained
confidential information about the opposing party. Id. The
court set forth the test to be applied when counsel employs
a side-switching expert. Under the test, the court determines:
(1) Did the expert have confidential information pertaining
to the first retaining party’s trial preparation and strategy; (2)
did he disclose it to the counsel who subsequently retained
the expert; and (3) if so, does counsel’s continued representa-
tion threaten to taint all further proceedings? See, id.; Shadow
Traffic Network v. Superior Court, 24 Cal. App. 4th 1067, 29
Cal. Rptr. 2d 693 (1994).
   In Shadow Traffic Network, supra, Metro Traffic Control,
Inc. (Metro), was a competitor of Shadow Traffic Network
                  Nebraska Advance Sheets
	           MID AMERICA AGRI PRODUCTS v. ROWLANDS	319
	                      Cite as 286 Neb. 305

(Shadow Traffic) in the business of traffic reporting. Metro
sued Shadow Traffic for various business torts. Attorneys for
Metro interviewed members of an accounting firm to discuss
retention of the accounting firm as expert witnesses. Metro’s
counsel informed the accounting firm that the conversation was
confidential and proceeded to discuss trial strategies and theo-
ries. The accounting firm was ultimately not retained by Metro.
A few weeks later, attorneys for Shadow Traffic met with two
of the same accountants. The accountants told Shadow Traffic
that Metro’s attorneys had interviewed the firm for the same
purpose of testifying as an expert, but had decided not to retain
it. An attorney for Shadow Traffic spoke with another account­
ant who had discussed the case with Metro’s counsel. Shadow
Traffic then retained the accountant as a testifying expert and
disclosed to Metro they had done so.
    The trial court sustained Metro’s motion to recuse Shadow
Traffic’s attorneys. The appellate court articulated a test similar
to the test in North Pacifica, LLC v. City of Pacifica, 335 F.
Supp. 2d 1045 (N.D. Cal. 2004).
      “The party seeking disqualification must show that its
      present or past attorney’s former employee possesses
      confidential attorney-client information materially related
      to the proceedings before the court. . . . Once this show-
      ing has been made, a rebuttable presumption arises that
      the information has been used or disclosed in the cur-
      rent employment. . . .”
Shadow Traffic Network, 24 Cal. App. 4th at 1084-85, 29 Cal.
Rptr. 2d at 703 (quoting In re Complex Asbestos Litigation,
232 Cal. App. 3d 572, 283 Cal. Rptr. 732 (1991)). The test
served to “implement the important public policy of protect-
ing against the disclosure of confidential information and the
potential exploitation of such information by an adversary.”
Shadow Traffic Network, 24 Cal. App. 4th at 1085, 29 Cal.
Rptr. at 703.
    Using the test described in North Pacifica, LLC, the spe-
cial master proceeded to determine whether O’Neil obtained
confidential information from Horizon’s counsel and, if he
did, whether he disclosed such information to Lansing’s coun-
sel. Implicit in the test applied by the special master was the
    Nebraska Advance Sheets
320	286 NEBRASKA REPORTS



finding by the Respondent that Horizon reasonably believed
that the information it conveyed to O’Neil would be kept
confidential. We approve the special master’s use of this test.
A rebuttable presumption of shared confidences should be
applied to a side-switching expert. The party requesting a dis-
qualification of counsel that subsequently retained the expert
must establish that it reasonably believed that information it
conveyed to the expert would be kept confidential and that
it conveyed confidential information to the expert. If this is
shown, the presumption arises that this information was con-
veyed by the expert to counsel that subsequently retained the
expert. Counsel must rebut this presumption by proving that he
or she did not receive confidential information from the expert.
If the presumption is not rebutted, the court should determine
whether continued representation by counsel will taint fur-
ther proceedings.
   Horizon had the initial burden to show that it reasonably
believed that information conveyed to O’Neil would be kept
confidential and that it had conveyed confidential information
to O’Neil. When Horizon made this showing, it created the
rebuttable presumption that O’Neil conveyed the confidential
information to counsel for Lansing. To rebut this presumption,
Lansing’s counsel had to prove that O’Neil did not convey the
confidential information to counsel for Lansing.
   The special master accepted the factual findings of
the Respondent that O’Neil and Horizon had a confiden-
tial relationship and O’Neil had confidential information
which was conveyed to him by Horizon, but that at no
time did O’Neil communicate to Lansing’s counsel any of
the confidential information. And Horizon’s counsel had not
advanced any evidence that its trial strategies, work product,
or mental impressions had been communicated by O’Neil to
Lansing’s counsel.
   We review the findings of the special master to determine
whether such findings are clearly against the weight of the
evidence. Recommended factual findings of a special mas-
ter have the effect of a special verdict, and the report upon
questions of fact, like the verdict of a jury, will not be set
aside unless clearly against the weight of the evidence. See
                 Nebraska Advance Sheets
	          MID AMERICA AGRI PRODUCTS v. ROWLANDS	321
	                     Cite as 286 Neb. 305

Larkin v. Ethicon, Inc., 251 Neb. 169, 556 N.W.2d 44 (1996).
The special master’s finding that O’Neil did not convey the
confidential information to Lansing’s counsel was not clearly
against the weight of the evidence.
  Horizon has not shown clearly and convincingly that the
Respondent had a legal obligation to disqualify Lansing’s
counsel. Horizon is not entitled to a writ of mandamus. See
Schropp Indus. v. Washington Cty. Atty.’s Ofc., 281 Neb. 152,
794 N.W.2d 685 (2011).

                   2. District Court’s Order
                      Disqualifying O’Neil
   We address one remaining issue, because it is necessary for
complete resolution of this matter. The Respondent “sustain[ed]
the Motion to Disqualify . . . O’Neil . . . from testifying as
an expert witness.” The order prohibited O’Neil from tes-
tifying but did not expressly prohibit him from consulting
with Lansing.
   The special master concluded that continued representa-
tion by Lansing’s counsel did not threaten to taint further
proceedings, because O’Neil was disqualified as a testifying
expert. The Respondent accepted the testimony of Nesland
and Christie that they reasonably believed they had estab-
lished a confidential relationship with O’Neil and that O’Neil
received confidential information. It accepted the testimony
of May that O’Neil had not conveyed confidential informa-
tion to him. O’Neil was disqualified from testifying as an
expert witness to protect Horizon’s confidential information.
If, following his disqualification, O’Neil were to consult with
Lansing as a nontestifying expert, the proceedings would be
tainted. Therefore, we conclude the order implicitly prohibits
all further contact by O’Neil with Lansing and its counsel
and disqualifies O’Neil from any further participation in this
matter from and after the date of the disqualification order of
March 30, 2012.

                     VI. CONCLUSION
  There is a rebuttable presumption that O’Neil shared confi-
dences gained from Horizon’s counsel with Lansing’s counsel.
    Nebraska Advance Sheets
322	286 NEBRASKA REPORTS



Lansing rebutted this presumption, because the special mas-
ter determined that O’Neil had not communicated Horizon’s
confidential information to Lansing’s counsel. This finding
is not clearly against the weight of the evidence. We adopt
this finding, and conclude that because O’Neil did not share
confidential information with Lansing or Lansing’s counsel,
disqualification of Lansing’s counsel is not required. Horizon’s
application for a writ of mandamus is denied.
                                   Writ of mandamus denied.
   Miller-Lerman, J., not participating.
