Continuity mistake: Marion Hammond unlocks the boat door and finds a mess. Between the establishing shot of the interior and the one with Tom Selleck inside, the towel on the ladder moved, and a diary tossed on top of the typewriter flipped without anyone coming anywhere near. (00:10:05)
Continuity mistake: On his way to Rick's boat, Magnum stops to talk with the witch lady. A very short drive and he's then in front of the boat. Rick is in the background and he starts moving and preparing to greet him, but in the close-up it's as if he has been chilling all along and only then decides to be active. (00:21:20)
Continuity mistake: Magnum is saved, and it's time for the others to concern themselves with the assailant. Rick dives in a close-up to look for him. The mask is really close to him all of a sudden, and in a different position (practically touching Magnum's chest) in next shot. (00:23:20)
Continuity mistake: When Marion asks "He's dead, isn't he?" hair pops in front of her shoulder suddenly after the cut. In fact, throughout the whole scene notice how in close-ups it's in front of her shoulder, in wider ones behind her back. (00:24:25)
Continuity mistake: Higgins wants to show Magnum the rare Kudu buck in a book. Picking it up from the shelf, causes 3 other books to lean forward. In the close-up that follows, just one book is misplaced. (00:26:30)
Continuity mistake: Magnum puffs holding Keone's photo with his right hand - which was both hands before the sudden cut. He then drops the photo on the table, but when he digs the map from underneath the pad, the photo changes position entirely again during a sudden cut. (00:29:30)
Continuity mistake: After the culprit and Marion are aboard safely, there's a shot of Magnum with the bomb in close-up, followed by another one where the timer went back almost at the starting point. (00:44:40)
Continuity mistake: To nobody's surprise, Magnum emerges from the ocean unscathed. Between shots, his hand and Rick and the villain's change positions. (00:45:15)
Continuity mistake: Marion and Magnum walk to the taxi for the goodbye. He opens the door, and her hair is all behind her back. Switching to the frontal view, she has her ponytail in front of the left shoulder. (00:46:00)
