Privilege waiver concepts can be confusing, even in a context of a lawyer representing one client. Additional complexities arise in the common scenario of one lawyer representing multiple clients on the same matter.
In Anderson v. Clarksville Montgomery County School Board, 229 F.R.D. 546 (M.D. Tenn. 2005), a lawyer represented 80 plaintiffs suing a school board. One of the clients shared the lawyer’s letters with school board officials. The magistrate judge found that a single plaintiff could not waive the attorney-client privilege that belonged to all of the clients, even if he deliberately discloses the privileged communications to the defendant. The judge ordered the defendant to destroy the letters without reading them, and entered an order prohibiting all the plaintiffs from sharing privileged communications with the defendant.
Lawyers on either side of a case involving multiple clients should remember that a waiver normally requires a unanimous vote by the jointly represented clients.