In 1998, Tom Leahy worked with his young associate, Peter D. Hoste, preparing for a complex medical-malpractice trial. The two plaintiff lawyers were in the office on a Saturday, planning for the cross-examination of a main defense witness scheduled for two days later. Hoste told Leahy he would be in the office first thing on Sunday morning. Leahy replied that he would not arrive until the afternoon, which drew a panicked look from Hoste. “He just looked at me, shook his head and said, ‘Trust me, it …