From The Perry Mason TV Show Book
This is the unique episode where Lt. Tragg is surprised to see Mason and Burger working on the same side.

While on vacation, Hamilton Burger introduces his fellow duck-hunters to Jeff Pike, an old friend who saved his life in a boating accident twelve years before. Now Jeff is in trouble and wants Hamilton's advice. Jeff and his son are at odds with a man who is later murdered. Since the L.A. District Attorney's office has jurisdiction, Hamilton disqualifies himself and asks Perry to defend his friend.