Litigants accused of willful patent infringement sometimes rely on an "advice of counsel" defense. Interestingly, courts have recognized a distinction between such a defense in the privilege and the work product contexts.

In SB IP Holdings LLC v. Vivint, Inc., the court applied the majority view of the defense on the attorney-client privilege side: the "waiver extends to all communications relating to the same subject matter – that is, all communications relating to [the pertinent] Application." Civ. A. No. 4:20-CV-00886, 2022 U.S. Dist. LEXIS 206220, at *24 (E.D. Tex. Nov. 14, 2022). The court then turned to the work product waiver scope. Noting that "work-product waiver is narrower than attorney-client privilege waiver," the court stressed that an "advice of counsel" defense necessarily focuses on the accused "'infringer's state of mind.'" Id. at *25-26 (citation omitted). The court thus pointed to a Federal Circuit case in concluding that "work product that was never communicated to [the accused infringer] is not discoverable" – because it did not affect the accused infringers' state of mind. Id. at *26.

Lawyers considering any "advice of counsel" defenses in patent or other cases should first carefully analyze the scope of the resulting waiver.