Other mistake: The episode opens with the Coast Guard finding the boat owned by Marion's father empty. It's a small sailboat. Later Magnum visits it with Marion, and the boat is a small double decker yacht that looks entirely different. (00:01:50 - 00:09:30)
Magnum, P.I. (1980)
1 other mistake in Dead Man's Channel
Starring: Tom Selleck, Roger E. Mosley, John Hillerman, Larry Manetti
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)
Mac: Time has little to do with infinity and jelly donuts.
Trivia: Tom Selleck is the only actor to appear in every episode of the show.