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Articles on Law, Science, and Engineering

(see Expert Witness Liability)

When are Expert Witnesses Liable for their Malpractice?

By Edward P. Richards and Charles Walter, 19 IEEE Engineering In Medicine And Biology Magazine #2, 107-109.

[Update - 15 Aug 04 - Louisiana reaches the same result in Louisiana - Marrogi v. Howard, 805 So.2d 1118 (La. 2002). The Third Circuit distinguished LLMD in Huges v. Long, 242 F.3d 121, 242 F.3d 121 (3d Cir. 2001), holding that court appointed experts are immune to malpractice claims by the parties to a case. Wyoming reached the same holding in Riemers v. O'Halloran, 2004 N.D. 79, 678 N.W.2d 547, 2004 ND 79 (N.D. 2004). Wyoming held that attoneys can be sued for negligence in retaining experts - Rino v. Mead, 2002 WY 144, 55 P.3d 13 (Wyo. 2002). see Evidence & Causation]


Expert witness testimony is essential to all legal proceedings that involve technical, medical, professional, or scientific matters. More generally, experts must testify whenever the underlying matters are beyond the common knowledge of lay jurors. As we have written in previous articles, the courts have spend much time and energy determining how to access the proper qualifications for experts.  Without an expert, a plaintiff cannot proceed to trial, and a defendant is usually doomed to an adverse jury verdict. Since experts are often a scarce resource that is essential to litigation, many charge substantial fees for their services.  If the expert does not do a good job, the party employing the expert will lose the lawsuit as well as be responsible for the expert's fees.

This article deals with expert witness malpractice.  Should the party hiring the expert be entitled to sue the expert for malpractice? Should the party that the expert testifies against be allowed to sue the expert? Conversely, what are the legal risks of being an expert witness?

What is Expert Witness Malpractice?

There are two parties concerned with the performance of experts: the party that hires the expert to testify and the opposing party. Their goals are at odds.  The hiring party wants effective testimony as measured by a beneficial effect on the judge and jury, while the opposing party wants the expert discredited and the testimony stricken.  Dissatisfaction by either party, without more, is not evidence of malpractice.  As in other malpractice actions, it must be found that the expert performed below the standard for the profession he/she represents, and that this substandard behavior caused the party's injuries.  Thus the party claiming malpractice must show both the standard for such experts and that, but for the expert's deviation from the standard, the party would have won.  However, unlike other malpracticing professionals, the expert witness occupies a privileged place in the legal system. This is illustrated in the recent case, LLMD of Michigan v. Jackson-Cross.[1]

This case began when plaintiff Wintoll sued a group of lenders for not honoring their commitment to finance an industrial rehabilitation project.  After the lawsuit commenced, plaintiff, through his attorney, contacted the expert, Charles Seymour, chairman of Jackson-Cross.  Plaintiff needed testimony on the valuation of the lost business opportunity and other costs associated with the defendant's conduct.  Without this testimony, plaintiff would not be able to present a credible case for damages to the jury.  Seymour responded with a proposal for professional services, which were to include quantifying the damages sustained because of the lenders' failure to close under the mortgage commitments; preparing a signed report outlining what was done, stating the conclusions and supporting them; and participating in pre-trial conferences, depositions and trial.  Plaintiff, through his attorney, accepted Seymour's proposal.

Seymour provided Wintoll with a calculation of lost profits of $6,000,000.  This calculation was performed by an employee of Jackson-Cross using a spreadsheet program.  While the court is silent on pretrial discovery, it appears that Seymour was not deposed prior to trial and first testified about this calculation on the stand before the jury.  On cross-examination, defense counsel showed that the damages calculation was based on an underlying mathematical error which rendered the calculation useless.  Seymour conceded the error, and also was forced to admit that he could not correct the calculation because he did not prepare the original report.  This so undermined his credibility as a witness that the judge struck his testimony.  Wintoll was forced to rely on a much lower estimate based on other witness testimony, and agreed to settle the case for $750,000.  Seymour subsequently provided a corrected estimate of $2,700,000 in lost profits, and Wintoll sued him and Jackson-Cross for the difference.

Seymour defended with a claim of witness immunity: the right of a witness in a legal proceeding to testify without fear of legal retribution.  What seemed a simple malpractice case was now cast as a complicated public policy choice between an alleged need to encourage testimony by paid witnesses and assuring that expert witnesses testify in a professional manner.

Witness Immunity

There are two types of witness immunity; immunity against criminal prosecution based on the testimony and immunity against civil liability for harm caused by the testimony.  If a witness lies on the stand or in deposition, the witness may be prosecuted for the crime of perjury.  All witnesses at all times, irrespective of any immunity claims, are subject to perjury charges if they lie in sworn testimony. Witnesses may also be prosecuted for crimes that they admit to in testimony, unless the government has granted them immunity for testimony. In the case of perjury and admitted crimes, the prosecutions are brought by government prosecutors and not by the parties to the lawsuit.  They provide no remedy for a private party injured by expert witness malpractice or other civil wrongs, such as defamation by the witness.  Private parties must bring lawsuits under tort law or under specific statutes that provide remedies for the underlying harm.  The leading United States Supreme Court case on witness immunity, Briscoe v. LaHue,[2] arose from a private action for deprivation of civil rights under a federal law.

There were two sets of plaintiffs in this case.  Both alleged that they were the targets of perjured testimony in their criminal trials and were convicted solely on false testimony.  In one case, defendant police officer allegedly lied about the fingerprint evidence, claiming that it showed that plaintiff was at the crime scene.  The evidence itself was a partial fingerprint which expert analysis showed was insufficient to identify plaintiffs.  In the other case, defendant police officer allegedly gave false testimony indicating that plaintiffs had fabricated their alibi testimony to the police.  The police officers denied the allegations and asserted witness immunity as a defense to all claims.  The lower court dismissed the plaintiff's claims, finding that the police officers, as witnesses, were entitled to complete immunity from claims by persons injured by their testimony.  The United States Supreme Court accepted the case for review and began its analysis with an inquiry into the public policy basis for witness immunity:

"The immunity of parties and witnesses from subsequent damages liability for their testimony in judicial proceedings was well established in English common law. Some American decisions required a showing that the witness' allegedly defamatory statements were relevant to the judicial proceeding, but once this threshold showing had been made, the witness had an absolute privilege. The plaintiff could not recover even if the witness knew the statements were false and made them with malice. ... the claims of the individual must yield to the dictates of public policy, which requires that the paths which lead to the ascertainment of truth should be left as free and unobstructed as possible.  A witness' apprehension of subsequent damages liability might induce two forms of self-censorship. First, witnesses might be reluctant to come forward to testify. And once a witness is on the stand, his testimony might be distorted by the fear of subsequent liability. Even within the constraints of the witness' oath there may be various ways to give an account or to state an opinion. These alternatives may be more or less detailed and may differ in emphasis and certainty. A witness who knows that he might be forced to defend a subsequent lawsuit, and perhaps to pay damages, might be inclined to shade his testimony in favor of the potential plaintiff, to magnify uncertainties, and thus to deprive the finder of fact of candid, objective, and undistorted evidence. But the truth finding process is better served if the witness' testimony is submitted to the crucible of the judicial process so that the factfinder may consider it, after cross-examination, together with the other evidence in the case to determine where the truth lies."[3]

The United States Supreme Court concluded that the common law provides complete immunity from lawsuits against witnesses, unless this policy is modified by subsequent legislation.  The court then noted examples of such subsequent modification, such as laws punishing perjury.  The court did not find that the civil rights statutes used by plaintiffs abrogated witness immunity and affirmed the dismissal of plaintiff's complaints.

Resolving the Wintoll Case

Based on the Briscoe case, the trial court accepted Seymour's claim of witness immunity and granted summary judgment for the defendant. The appeals court affirmed the summary judgment, affirming that the doctrine of witness immunity barred the plaintiff's claim against the expert.  The Pennsylvania Supreme Court accepted the case on the issue of whether witness immunity applies to a party's own witnesses.

The lower court in Wintoll based its opinion on an earlier Pennsylvania case, Panitz v. Behrend, 273, 632 A.2d 562 (1993).  In Panitz, a physician expert witness was asked to prepare testimony on the effects of exposure to formaldehyde in building materials, and to explain why exposure to such materials had a different effect than did exposure to formaldehyde in cigarettes. The expert initially represented to the party who was hiring her that she could address this problem, but during cross-examination she testified that she couldn't explain the difference in reactions between exposure to building materials and cigarettes. She later stated that she had found that her earlier analysis had been inaccurate, but she did not tell the party who hired her that she could not explain the difference if requested to do so on cross- examination. The law firm which retained her refused to pay her bill, and she sued. The law firm counterclaimed, alleging professional malpractice.  The court found that public policy supported witness immunity in this case. The witness had testified truthfully and accurately, the law firm's claim being that it was dissatisfied with the outcome of the testimony.  The court found that allowing the party who engaged the witness to sue under these circumstances would encourage experts to shade their testimony toward the side retaining them.

This analysis is, of course, wrong. The only restraint on expert witnesses who make incorrect representations to obtain employment is to hold them responsible when they get caught during cross- examination. The court's failure to hold the expert in Panitz responsible encourages experts to conceal unfavorable information and give misleading testimony to gain employment because they have nothing to lose when they get caught.

The plaintiff argued that his case was different from Panitz. The expert in Panitz had corrected the error in her pre-testimony analysis and had testified truthfully and accurately to the court. In contrast, Seymour had not detected the mistake until it was pointed out by defense counsel, and then was unable to do the calculation necessary to correct the mistake.  Unlike Panitz, Wintoll was unhappy with the negligent preparation for the testimony, not just with the unfortunate effect of the testimony. He argued that sheltering such negligence under witness immunity would not advance the public's interest in accurate expert testimony.  The Pennsylvania Supreme Court was sympathetic to plaintiff's claims, but was also concerned about undermining the policy behind witness immunity:

"It is imperative that an expert witness not be subjected to litigation because the party who retained the expert is dissatisfied with the substance of the opinion rendered by the expert. An expert witness must be able to articulate the basis for his or her opinion without fear that a verdict unfavorable to the client will result in litigation, even where the party who has retained the expert contends that the expert's opinion was not fully explained prior to trial. Application of the witness immunity doctrine in Panitz was consistent, therefore, with the two-fold policy of the doctrine: to ensure that the path to the truth is left as free and unobstructed as possible and to protect the judicial process."[4]

The Pennsylvania Supreme Court then distinguished Panitz by categorizing the claim against the expert witness there as one which attacked the "substance" of the expert's opinion whereas the claim in Wintoll as being premised on the allegation that the expert was "negligen[t] in formulating [his] opinion."[5] The court found that public policy of encouraging accurate testimony by expert witnesses was better served by making the witness liable for negligent preparation of testimony than by immunizing such negligence. The court took care, however, to state the limits of this ruling:

"We caution, however, that our holding that the witness immunity doctrine does not preclude claims against an expert witness for professional malpractice has limited application. An expert witness may not be held liable merely because his or her opinion is challenged by another expert or authoritative source. In those circumstances, the judicial process is enhanced by the presentation of different views. Differences of opinion will not suffice to establish liability of an expert witness for professional negligence."[6]

However, in his dissenting opinion, Justice Cappy pointed out that the distinction between claims based on "the substance" versus "the formulation of the substance" of expert testimony is elusive at best.[7] He characterized the lawsuit in Panitz as premised on the allegation that she had been negligent in formulating her opinion, and not an attack on the substance of the opinion she offered on cross-examination. Justice Cappy pointed out:

"In fact, there is a lengthy discussion in [Panitz] concerning the contention by the [plaintiff] that 'it was not the in-court testimony that caused the loss but the pre-trial representations about what the in-court testimony would be.' Panitz, 632 A.2d at 565. Clearly, the Behrend firm sued Panitz premised upon Panitz's negligent failure to inform them that she had changed her opinion prior to trial; I see nothing in Panitz which would indicate that the Behrend firm sued Panitz on the basis that they somehow disagreed with the substance of her opinion."[8]


Expert witnesses have always been subject to prosecution for perjury for false testimony.  The Pennsylvania Supreme Court has now expanded the liability of expert witnesses to include negligence in the preparation of testimony. The Court made the distinction between "substance" and "preparation" to avoid overruling the older ruling in Panitz. However, this distinction is illusory and will not be easily made in future cases. Either the courts will go back to the old rule designed for unpaid witnesses, or they will follow the trend in Wintoll and extend malpractice liability to experts who do not perform within the standard of their profession. Since the rule in Wintoll promotes the presentation of reliable expert testimony better, it will probably be widely adopted by the courts.

The court was silent on whether this liability is limited to the party hiring the expert, or to anyone who is injured by the expert. If the liability is based on the contract between the expert and the party employing the expert, then it would be expected that only the employing party could sue. If the liability is based on a tort theory of malpractice, it is possible that an opposing party injured by the negligence could sue the expert. The likely outcome is that the courts will adopt the rule that will better promote reliable expert testimony. Moreover, principles of collateral estoppel should bar suits based on lawsuits that were lost because of inaccurate testimony by the other party's expert. In addition, the option of suing the lawyer who let it happen is available and much more appealing than suing the expert who outsmarted him.

This case should be reviewed by any one who is employed as an expert witness. This is an important change in the law in Pennsylvania and may portend a trend in other states. Experts should consider redrafting their retainer contracts to subject malpractice disputes to arbitration.


[1] LLMD of Michigan, Inc. v. Jackson-Cross Co., 740 A.2d 186 (Pa. 1999).

[2] Briscoe v. LaHue, 460 U.S. 325 (1983).

[3] Briscoe v. LaHue, at 332-333, internal citations and quotation marks deleted.

[4] LLMD of Michigan at 191.

[5] LLMD of Michigan at 191.

[6] LLMD of Michigan at 191.

[7] LLMD of Michigan at 192.

[8] LLMD of Michigan at 192.

End of document

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