Clients and lawyers asserting claims against each other can waive privilege protection without disclosing any privileged communications. But such implied or "at issue" waivers often require balancing of participants' interests. For instance, some courts hold that clients suing their former lawyers for malpractice must disclose their communications with successor counsel. Other courts take the opposite position, finding such intrusion inappropriate.
In Heth v. Satterlee Stephens Burke & Burke LLP, No. 650379/2015, 2019 NY Slip Op 30555(U) (N.Y. Sup. Ct. Mar. 5, 2019), the court dealt with a malpractice defendant's efforts to discover communications between the plaintiff former client and the defendant's co-counsel – not its successor counsel. The court allowed such discovery, explaining that the disclosure of such communications between plaintiff client and the malpractice defendant's co-counsel was "essential" to defendant's defense that it "did not proximately cause [client's] alleged damages" – because the client had relied on co-counsel's rather than defendant's advice. Id. at 3.
While clients contemplating malpractice cases against their former lawyers may be able to protect their communications with successor counsel, they normally should not expect the same treatment for their communications with defendant's co-counsel during the pertinent time.