Conflict Checks

An expert conflict is not a lawyer conflict

The instinct to reason from the rules of professional conduct produces the wrong answer here. There is no expert analogue to Model Rule 1.7, no duty of loyalty running from a candidate expert to a party who once spoke to them, and no rule of procedure that disqualifies an expert for having worked for the other side before. Experts are not fiduciaries of the parties who retain them, and the same economist, engineer or physician routinely appears for plaintiffs in one matter and defendants in the next.

The doctrine that actually disqualifies an expert is built on confidential information. The concern is not that the expert has divided loyalties; it is that privileged material, work product or litigation strategy passed to a person who is now working for the opponent, and that no instruction can unsee it. Framed that way, the analysis follows the documents rather than the relationship.

Disqualification rests on the court's inherent power to supervise the conduct of proceedings before it — see Grant Thornton, LLP v. FDIC, 297 F. Supp. 2d 880 (S.D. W. Va. 2004) — rather than on any rule, and the party seeking disqualification carries the burden.

The two questions courts actually ask

The controlling formulation comes from Wang Laboratories, Inc. v. Toshiba Corp., 762 F. Supp. 1246 (E.D. Va. 1991), decided by Judge Ellis on 9 May 1991. Two questions:

“Was it objectively reasonable for the first party who claims to have retained the consultant … to conclude that a confidential relationship existed?”

“Was any confidential or privileged information disclosed by the first party to the consultant?”

“Affirmative answers to both inquiries compel disqualification.” 762 F. Supp. at 1248.

On the facts of Wang itself, the expert was disqualified. The first party had reasonably assumed a confidential relationship, and what had been disclosed included work product covering patent-prosecution analysis and litigation strategy — case-specific material of exactly the kind the doctrine exists to protect.

The conjunctive structure is the point of the test. A candidate who took a call from opposing counsel is not thereby unavailable. A candidate who received a privileged memorandum from opposing counsel probably is. Many courts add a third step, weighing the public interest in preventing sham retentions and protecting confidences against freedom of contract, the prejudice to the second retaining party and the availability of other experts: see Cordy v. Sherwin-Williams Co., 156 F.R.D. 575 (D.N.J. 1994), and Paul v. Rawlings Sporting Goods Co., 123 F.R.D. 271 (S.D. Ohio 1988), which rejected automatic disqualification.

The second prong is where the motion is won

Most contested motions turn on whether what passed was confidential information at all. Courts look at whether the material was case-specific rather than general background; whether it was genuinely privileged or confidential; whether it would have been discoverable anyway, in which case its disclosure to the candidate changed nothing; and whether it was already public.

Purely technical background usually fails that test. Explaining how a class of products works, or walking a candidate through publicly filed documents, does not convey confidential information no matter how long the conversation ran. Counsel's assessment of the weaknesses in the client's own case, an unfiled analysis, a settlement posture or a litigation strategy is the opposite, and passing any of it to a candidate before a conflict check is what creates the problem.

The practical consequence for the first party is that the record made at the time of the contact decides the motion years later. Notes of what was described, copies of what was sent, and the date and duration of each call are the evidence on the second prong. A party that cannot show what was disclosed will struggle to prove that anything confidential was.

The exploratory call, and why the test is not automatic

The first prong resists the tactic of making token contact with every plausible candidate in order to deny them to the opponent. Courts examining whether a confidential relationship was objectively reasonable look at whether there was a written retention agreement, whether confidential documents were actually sent, how many communications there were, whether any fee was paid, and whether the expert formed or expressed an opinion. A single exploratory call, without documents and without payment, generally does not create the relationship.

Wang itself says as much, observing that disqualification does not seem warranted where no privileged or confidential information passed — which is precisely why the two-part test exists rather than an automatic bar. A rule that disqualified any expert who had ever spoken to the other side would make conflicting-out a purchasable litigation tactic.

Courts have declined to disqualify where the overlap was superficial. In Bone Care International, LLC v. Pentech Pharmaceuticals, Inc., 2009 WL 249386 (N.D. Ill. Feb. 2, 2009), an expert who had testified for opposing sides on distinct patents with no overlap was permitted to continue; see also Ngo v. Standard Tools & Equipment Co., 197 F.R.D. 263 (D. Md. 2000). Where the overlap was real, they have disqualified: In re Diet Drugs Products Liability Litigation, 2009 WL 1886131 (E.D. Pa. 2009), involving an expert previously retained by the defendant in an analogous toxic tort matter, and W.R. Grace & Co. v. Gracecare, Inc., 152 F.R.D. 61 (D. Md. 1993), where the expert had previously consulted with opposing counsel in the same case.

How a check is actually run

A conflict check that consists of asking the candidate whether they have a conflict is not a check. The candidate cannot answer the question without the list, and the list is longer than the caption.

• Every party, with corporate parents, subsidiaries and affiliates named individually.
• Insurers and indemnitors, which frequently do not appear in the caption at all.
• All counsel of record, on both sides, because a prior retention by the opposing firm in an unrelated matter is worth knowing about even where it disqualifies nobody.
• The subject matter itself — the product, patent, site, facility, transaction or event at issue.
• The candidate's own side of the ledger: current and former employers, consulting clients, board seats, equity holdings and academic funding sources.

It is a continuing obligation rather than a one-time exercise. Model retention language requires the expert to notify counsel immediately of any conflict arising later in the engagement, and of any subpoena received in another matter. Engagements run for years; the candidate's client list does not stand still while they do.

When a conflict surfaces late

A conflict discovered after disclosure is a scheduling problem before it is a doctrinal one. If a testifying expert is disqualified after the FRCP 26(a)(2) deadline has passed, the party may be left with no disclosed expert on an issue it carries the burden on, and no time in which to disclose a replacement. Whether relief follows — leave to substitute, an extension of the expert schedule, a continuance — turns on the scheduling order and the court's discretion, not on the conflict doctrine. Courts have permitted substitution and extended discovery where an expert was removed for an improper engagement arrangement, but that is an exercise of discretion in a particular case rather than an entitlement.

Delay is its own hazard. A party that knows of a conflict and sits on it risks waiver: see Popular, Inc. v. Popular Staffing Services Corp., 239 F. Supp. 2d 150 (D.P.R. 2003). An objection held back for tactical timing may be treated as abandoned.

What relief short of disqualification looks like — screening, a limiting instruction, or an order restricting the scope of the testimony — is not systematically treated in the authorities, and no survey of those remedies was located. A party facing a late-surfacing conflict should not assume a middle course is available.

Struck, or merely impeached

The remedy question runs wider than conflicts, and courts do not answer it uniformly. When something about an expert's position is compromised, one line of authority treats the defect as going to admissibility and strikes the testimony; another treats it as going to credibility and leaves it to the jury, subject to cross-examination.

The clearest documented instance of that split concerns compensation rather than conflicts. Where a testifying expert has been retained on a contingent basis, district courts have excluded the testimony: Straughter v. Raymond, 2011 U.S. Dist. LEXIS 93068 (C.D. Cal. Aug. 19, 2011), where the court entered an order excluding the expert's opinions, reports and testimony on the ground that she had been retained on an improper contingent-fee basis; J & J Snack Foods Corp. v. Earthgrains Co., 220 F. Supp. 2d 358 (D.N.J. 2002); and Farmer v. Ramsay, 159 F. Supp. 2d 873 (D. Md. 2001). The Seventh Circuit took the other view in Tagatz v. Marquette University, 861 F.2d 1040 (7th Cir. 1988), treating a contingent arrangement as a matter of credibility that the jury may weigh rather than a bar to admission.

The lesson for a conflict check is the timing rather than the doctrine. Whichever line a court follows, the party that identified the problem before retention never has to argue about it. The party that identifies it after disclosure is arguing about remedy on someone else's schedule.

The full Wang opinion is reported at 762 F. Supp. 1246.

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Published 2026-08-12