Starring: Tom Selleck, Roger E. Mosley, John Hillerman, Larry Manetti
Under World - S5-E5
Revealing mistake: In the opening shots of TC's helicopter, in one shot there are two helicopter shadows being cast on the water below, one shadow is TC's chopper and the other shadow is the filming chopper. The helicopter also changes between the T-tailed, Y-tailed, and different type skids. (00:01:30)
Don't Eat the Snow in Hawaii - S1-E1
Continuity mistake: When Magnum drops the ring out of the envelope, nothing is near it as it's shaking. In the close up shot, it's next to keys. (00:44:20)
Trivia: Tom Selleck is the only actor to appear in every episode of the show.