Garry Shandling was an irreverent stand-up comedian from Los Angeles. Bill Isaacson is a hard-charging antitrust litigator at one of the country’s powerhouse firms, Boies, Schiller & Flexner, in Washington, D.C.

Their 18-year friendship was as unlikely as it was strong. Then again, the bond between lawyer and client is built on trust, which can foster a long friendship, Isaacson said.