The New Jersey Supreme Court won’t weigh in on a case in which a client’s guilty plea foreclosed a legal malpractice claim against a lawyer who advised the client to cooperate with law enforcement—despite lacking criminal law experience.

It’s a final victory for attorney Joseph Mecca after years of litigation, but the case brings to bear the question of when a lawyer—particularly a solo or general practitioner—must demur in offering advice outside his area of expertise.