Professor Colin Miller at Evidence Prof Blog thinks so, and links to a draft of his essay advocating the exception. The abstract of his essay references Alton Logan, a man wrongfully imprisoned for 26 years while lawyers who knew the identity of the actual killer stood mute in order to protect client confidences:
In 1982, Alton Logan was convicted of first degree murder based upon being the trigger man in a robbery gone wrong at a Chicagoland McDonald’s. What the jury who convicted Logan did not hear was that another man, Andrew Wilson, confessed to the crime Logan allegedly committed. The problem was that Wilson confessed to his attorneys, public defenders Dale Coventry and Jamie Kunz, who confirmed with the relevant authorities that they were bound by the rules of professional responsibility not to disclose their client’s confession. Coventry and Kunz did prepare an affidavit detailing Wilson’s guilt and in fact planned to come forward if Logan were given the death penalty. Ironically, two holdouts on the jury seemingly spared Logan’s life by voting against capital punishment, but in fact dealt him the same fate that would befall the affidavit, being locked up (Logan in a prison cell; the affidavit in a lock box). Pained by pangs of guilt, the public defenders convinced Wilson to allow them to reveal his guilt after his death, resulting in Logan’s eventual release from prison twenty-six years after he entered.
A tough situation, for sure. I’d be curious to know if Professor Miller’s essay makes any converts.