Rules of Professional Conduct: Rule 3.7--Lawyer as Witness
(a) A lawyer shall not act as advocate at a trial in which the lawyer is likely to be a necessary witness except where:
(1) The testimony relates to an uncontested issue;
(2) The testimony relates to the nature and value of legal services rendered in the case; or
(3) Disqualification of the lawyer would work substantial hardship on the client.
(b) A lawyer may not act as advocate in a trial in which another lawyer in the lawyer’s firm is likely to be called as a witness if the other lawyer would be precluded from acting as advocate in the trial by Rule 1.7 or Rule 1.9. The provisions of this paragraph (b) do not apply if the lawyer who is appearing as an advocate is employed by, and appears on behalf of, a government agency.
 Combining the roles of advocate and witness can prejudice the opposing party and can involve a conflict of interest between the lawyer and client.
 The opposing party has proper objection where the combination of roles may prejudice that party’s rights in the litigation. A witness is required to testify on the basis of personal knowledge, while an advocate is expected to explain and comment on evidence given by others. It may not be clear whether a statement by an advocate-witness should be taken as proof or as an analysis of the proof.
 Subparagraph (a)(1) recognizes that if the testimony will be uncontested, the ambiguities in the dual role are purely theoretical. Subparagraph (a)(2) recognizes that where the testimony concerns the extent and value of legal services rendered in the action in which the testimony is offered, permitting the lawyers to testify avoids the need for a second trial with new counsel to resolve that issue. Moreover, in such a situation the judge has firsthand knowledge of the matter in issue; hence, there is less dependence on the adversary process to test the credibility of the testimony.
 Apart from these two exceptions, subparagraph (a)(3) recognizes that a balancing is required between the interests of the client and those of the opposing party. Whether the opposing party is likely to suffer prejudice depends on the nature of the case, the importance and probable tenor of the lawyer’s testimony, and the probability that the lawyer’s testimony will conflict with that of other witnesses. Even if there is risk of such prejudice, in determining whether the lawyer should be disqualified, due regard must be given to the effect of disqualification on the lawyer’s client. It is relevant that one or both parties could reasonably foresee that the lawyer would probably be a witness.
 If the only reason for not permitting a lawyer to combine the roles of advocate and witness is possible prejudice to the opposing party, there is no reason to disqualify other lawyers in the testifying lawyer’s firm from acting as advocates in that trial. In short, there is no general rule of imputed disqualification applicable to Rule 3.7. However, the combination of roles of advocate and witness may involve an improper conflict of interest between the lawyer and the client in addition to or apart from possible prejudice to the opposing party. Whether there is such a client conflict is determined by Rule 1.7 or 1.9. For example, if there is likely to be a significant conflict between the testimony of the client and that of the lawyer, the representation is improper by the standard of Rule 1.7(b) without regard to Rule 3.7(a). The problem can arise whether the lawyer is called as a witness on behalf of the client or is called by the opposing party. Determining whether such a conflict exists is, in the first instance, the responsibility of the lawyer involved. See Comment to Rule 1.7. Rule 3.7(b) states that other lawyers in the testifying lawyer’s firm are disqualified only when there is such a client conflict and the testifying lawyer therefore could not represent the client under Rule 1.7 or 1.9. The principles of client consent, embodied in Rules 1.7 and 1.9, also apply to paragraph (b). Thus, the reference to Rules 1.7 and 1.9 incorporates the client consent aspects of those Rules. Paragraph (b) is designed to provide protection for the client, not rights of disqualification to the adversary. Subject to the disclosure and consultation requirements of Rules 1.7 and 1.9, the client may consent to the firm’s continuing representation, despite the potential problems created by the nature of the testimony to be provided by a lawyer in the firm.
 Even though a lawyer’s testimony does not involve a conflict with the client’s interests under Rule 1.7 or 1.9 and would not be precluded under Rule 3.7, the client’s interests might nevertheless be harmed by the appearance as a witness of a lawyer in the firm that represents the client. For example, the lawyer’s testimony would be vulnerable to impeachment on the grounds that the lawyer-witness is testifying to support the position of the lawyer’s own firm. Similarly, a lawyer whose firm colleague is testifying in the case should recognize the possibility that the lawyer might not scrutinize the testimony of the colleague carefully enough and that this could prejudice the client’s interests, whether the colleague is testifying for or against the client. In such instances, the lawyer should inform the client of any possible adverse effects on the client’s interests that might result from the lawyer’s relationship with the colleague-witness, so that the client may make a meaningful choice whether to retain the lawyer for the representation in question.