by Paul A. Stewart

Attorneys are sometimes called upon to serve as testifying expert witnesses. This happens frequently when attorneys are asked to testify regarding the standard of care in legal malpractice actions. But it arises in other contexts as well, such as when attorneys in patent cases are asked to provide expert testimony regarding the often arcane procedures of the Patent and Trademark Office. A question the attorney must immediately confront is what ethical duties arise that are relevant to his or her service as an expert witness. In particular, may the attorney testify in matters adverse to a current or former client of the attorney or the attorney’s law firm? Until now, there has been very little guidance on this issue.

That, however, may soon change. The State Bar of California Standing Committee on Professional Responsibility and Conduct (COPRAC) recently released for public comment a draft Formal Opinion regarding the ethical conflict issues that may arise in this exact context. If the Formal Opinion is adopted after the public comment period, it should provide substantial guidance in this important area.

COPRAC assumes for purposes of the opinion that an attorney serving as an expert witness is not engaging in the practice of law within the meaning of the Rules of Professional Conduct, and thus ordinarily is not entering into an attorney-client relationship. As a result, many of the ordinary conflict-of-interest rules governing attorneys do not apply. For example, Rule 1.7(a), which prohibits an attorney from representing a client adverse to a current client without informed written consent, is inapplicable to an attorney testifying as an expert witness. Similarly, Rule 1.9(a), which prohibits an attorney from representing a client adverse to a former client in a matter substantially related to the attorney’s prior work without informed written consent, is also inapplicable to an attorney testifying as an expert witness.

This, however, does not mean that there are no ethical rules governing attorneys who testify as expert witnesses. Take, for example, the situation where an attorney first serves as an attorney in a traditional role for a client, and then subsequently serves as an expert witness adverse to that former client. Though Rule 1.9(a) itself does not bar this conduct because the expert is not representing a client adverse to a former client, other ethical duties to former clients are not dependent on whether the lawyer is engaged in legal representation of the subsequent client. As set forth in the comments to Rule 1.9, lawyers have two separate duties to former clients, the latter of which is codified in Rule 1.9(c), that may restrict an attorney’s ability to testify as an expert witness adverse to a former client.

First, the attorney may not “do anything that will injuriously affect the former client in any matter in which the lawyer represented the former client.” Thus, the attorney’s testimony must not cause harm to the former client in the matter in which the attorney previously represented the former client. The key here is that this restriction is limited to the specific matter in which the attorney previously represented the former client. The attorney’s expert testimony will, of course, be harmful to the former client in the current expert-witness matter, but unless the current expert-witness matter is the same matter in which the attorney previously represented the client, this duty would likely not prohibit the expert testimony.

Second, the attorney may not “at any time use against the former client knowledge or information acquired by virtue of the previous relationship.” COPRAC concludes that this restriction may bar the attorney’s expert testimony whenever competent performance of the attorney’s role as an expert would foreseeably require use or disclosure of confidential information acquired in the prior relationship. This, in turn, depends at least in part on whether there is a “substantial relationship” between the two engagements.

The substantial relationship test, of course, is a familiar one to all attorneys. Rule 1.9(a) generally prohibits an attorney from representing a new client adverse to a former client if the two matters are substantially related. Thus, while COPRAC concludes that Rule 1.9(a) does not directly apply to expert witness relationships, COPRAC still would apply the substantial relationship test from that Rule to determine whether an attorney may testify as an expert adversely to a former client. Accordingly, before taking on an expert witness engagement adverse to a former client, an attorney must conduct an ethical analysis similar to that of one seeking to act as an attorney adverse to a former client.

COPRAC also addressed the reverse situation, where an attorney first testifies as an expert witness and then serves as an attorney in a traditional role adverse to the attorney-expert’s former employer. In this situation, the two restrictions discussed above that derive from Rule 1.9(c) and the comments to Rule 1.9 do not apply. For example, the first restriction prohibits an attorney from doing anything that injuriously affects a “former client” in connection with the prior matter. However, the attorney-expert did not form an attorney-client relationship in the first matter. Thus, this restriction is inapplicable. Similarly, the second restriction prohibits an attorney from using against a “former client” any confidential information acquired in the first matter. Again, this is inapplicable because the party that retained the attorney-expert in the first matter is not a former client.

Ultimately, the only ethical conflict restrictions COPRAC identifies for an attorney who previously testified as an expert are the express and implied limitations arising from the attorney-expert’s engagement agreement with the party that retained the attorney as an expert witness. For example, the engagement agreement may require the testifying expert not to act adversely to the retaining party or disclose the retaining party’s confidential information. The attorney is, of course, bound by these lawful contractual provisions. Moreover, if abiding by those restrictions would materially limit the attorney’s ability to represent the client as an attorney in the new matter, then Rule 1.7(b) requires the attorney to disclose the material limitation to the client and obtain the client’s informed written consent to proceed with the representation. In addition, even if there is no material limitation on the attorney’s representation, Rule 1.7(c) still requires written disclosure to the new client of any ongoing contractual duties of confidentiality owed to the party who previously retained the attorney-expert.

Finally, COPRAC addressed the situation where the attorney-expert plans to testify as an expert witness adverse to a current client of the attorney’s law firm. The current client is represented by the attorney’s law firm in a matter wholly unrelated to the expert testimony, and the attorney-expert has never done any work for the firm’s current client.

In this situation, the basic conflict rule governing conflicts with current clients—Rule 1.7(a)—is inapplicable because the testifying expert is not representing a client as an attorney. In addition, because the expert witness matter and the attorney-client matter are wholly unrelated, it is unlikely that the law firm’s representation of its client will be materially limited by the attorney-expert’s work. Thus, Rule 1.7(b) is also inapplicable.

As a result, as long as the attorney-client matter and the expert witness matter are unrelated, there are not likely to be any substantial ethical conflict restrictions on an attorney testifying as an expert adverse to a current client of the attorney’s law firm. Of course, if the two matters are substantially related or are the same, it seems clear that the law firm would be precluded from both representing the client and also having one of its attorneys testify as an expert witness against that same client. Though not addressed by COPRAC, there would seem to be little doubt that such an arrangement would pose an unreasonable risk that the client’s confidential information would be used by the attorney-expert in a manner harmful to the client. In addition, the expert witness work would materially limit the law firm’s ability to represent its client effectively. The party working with the attorney-expert would certainly argue to the jury or judge that the opposing attorneys have no credibility because a member of their own law firm is appearing as a witness for the other side. Thus, the attorneys in a single law firm cannot be on both sides of the same case or substantially related cases, even if one of the attorneys is only serving in an expert witness capacity.

We will need to wait and see whether COPRAC’s proposed Formal Opinion is adopted without significant change after the public comment period. If it is largely unchanged, it will provide important guidance to attorneys and law firms engaged in providing expert witness testimony. Because the attorney-expert is generally not engaged in legal representation, many of the traditional conflicts rules governing attorneys are inapplicable. However, an attorney-expert still must be careful not to testify adversely to a current or former client in a matter substantially related to the work the attorney has done for the client in the role of an attorney.

Paul A. Stewart is a partner in the law firm of Knobbe, Martens, Olson & Bear, LLP, based in Irvine, California. Mr. Stewart’s practice focuses on intellectual property litigation. In addition, he serves as Chairman of the firm’s Ethics Committee, and is a member of the Orange County Bar Association Professionalism and Ethics Committee. He can be reached at paul.stewart@knobbe.com.