Other mistake: In a cute scene, the lads are helping Higgins pamper Magnum for his nefarious needs. So one of them drops a dry towel for Magnum on the stone platform he uses to come out of the tidal pool. It's a nice scene, but the stone block is isolated in water thigh-deep for 6'3" tall Tom Selleck, and one the doberman has trouble getting off from - you can see him look at the trainer off camera and then do a very awkward dive at the end. So there's no way that dog could have brought Magnum a towel, at least a DRY towel. (00:17:30)
Other mistake: At the USS Arizona Memorial, Judge Caine has flashbacks from the attack on Pearl Harbour, but he can't keep them in the correct aspect ratio. It's footage from a war movie (Tora! Tora! Tora!) but in the wrong proportions, so he's daydreaming of rather chunky Japanese planes. (00:39:10)