A plaintiff cannot sue an attorney for legal malpractice when that attorney had no duty to represent him, a state appeals panel ruled earlier this month.The ruling from the 3rd District Appellate Court in Ottawa undermined plaintiff Bret Johnson’s attempt to scuttle the agreement that placed his sister solely in charge of their deceased mother’s trust.Jean Sztajer created a living trust in May 2001 and named her three children — Sivi Polit, Bret Johnson and Sean Johnson — as successor co-trustees.In …