Visible crew/equipment: When in the opening credits the names of the special guest stars Donnelly Rhodes and Elaine Joyce appear, on the side of the Pitts Special you can see the reflection of the set lights. (00:03:50)
Continuity mistake: Marina does a Bette Davis on Magnum and then turns around to leave. She stands in the middle of the entrance, with still her glass in hand. Quick cut to Magnum, and the glass conveniently disappeared. (00:26:55)
Character mistake: The Grim Reaper is at the party to grab the paper copy of the will - however, after Magnum is incapacitated turtle-style, the guy never bothers to actually retrieve it from the mantle he put it on, nor Magnum checks out what the piece of paper is. (00:35:05)
Continuity mistake: Magnum hears a noise at the bottom floor and starts walking downstairs. In the shot right before the close-up of his foot breaking the step, at the top of the stairs you can see some candles he was not carrying and are not consistent with the illumination of the scene - in fact you can see Magnum with candles only in a brief shot in the 'teaser' before the opening credits, in a scene that was left out of the episode. (00:28:40)
Character mistake: Carlton's favourite gun is a Colt "Bisley Model", rare and produced starting 1894. When he introduced it to Magnum in the cabinet he called it a "Colt 45, vintage 1860" (or sixty-something, as Magnum started his line when he might have not finished). (00:16:50)
Continuity mistake: When Wilson MacLeish is kneeling on the golf course, the light changes drastically between close-ups (shadows) and wider angles (strong sunlight on the chest). (00:45:10)
Continuity mistake: In the hilarious stretched out comedy scene with Magnum trying to chase the suspect in his armor, whenever he is shown charging at the door and eventually breaking in, he is wearing the sword that he never retrieved - and in the moments when it's Tom Selleck in the armor and not a stuntman, he is not wearing it. (00:37:00)
Continuity mistake: In the epic clash between Canned Magnum and the Reaper, Magnum falls on his back and the sword falls back on his arm. When the Reaper walks past him, the sword is on the floor by his leg, but it goes back to the precarious position on his arm when he is flailing his arms crying for help. (00:35:35)
Continuity mistake: When the Grim Reaper closes the safe, in close-up his hooded head casts a shadow on the door. Cut to a wider shot, and the shadows changed. Likewise, in this wider shot he puts the painting back in place and the scythe casts a very oblique shadow, but in the shot when he reacts to Sir Thomas' arrival the shadow is vertical and his head casts a visible one too. (00:34:55)
Continuity mistake: At the entrance of the masquerade, in the close-ups of John Hillerman (starting when he says "However difficult this may be to say") you can see Carlton in the background, which is incoherent with the reciprocal positions in the shots of the hall. (00:31:40)
Continuity mistake: Magnum gives Marina the glass of scotch. When she nervously laughs saying "We all did", she is holding her glass with one hand; in the same shot, the other hand joins, but in the reverse shot it's not there, and back there as it returns to the previous angle. Moreover, the forefinger is at different heights in the separate shots, as shown by the level of scotch. (00:26:15)
Revealing mistake: Magnum takes an ancient gun from the cabinet and stumbles upon one of the eccentric millionaire's practical jokes. The joke though is an impossible one; the string that supposedly triggers it is not there, and when the gun goes off, Magnum is not holding the gun in a way that would pull it. (00:16:25)
Audio problem: The lawyer and Magnum join the others in the room for the reading (rather, play) of the will. One of the prospect heirs says "It's about time then", but their lips are not moving and the muffled and unnatural ambience makes it even further clear that it is dubbed in. (00:08:55)
Continuity mistake: After a breathtaking rendition of "Silent Night", Marina sits down. Next to her Simon is on the couch, who stretches his left arm placing it along the back of the couch, and the right arm goes on the armrest. Yet in the next shot he has both hands in his lap. (00:08:45)
Continuity mistake: The first time we see the blonde cousin, she is holding in her arms the picture of dear departed. Cut to a view of the room, and her right hand is at the top of the frame, completely different position from before. (00:08:00)
Continuity mistake: During the scene when Higgins comically 'abuses' Magnum and his sax skills, the shadow of the instrument on Magnum's chest changes position depending on the angle of the camera. Moreover, when Higgins mentions he came "on two accounts", Magnum tilts the sax back two times in two separate movements. (00:05:50)
Continuity mistake: Mr. MacLeish is in his plane, and before taking off he presses Play on the cassette player. He is holding it in a different way (fingers on opposite sides of the tape lid) between shots. (00:03:40)
Audio problem: Not getting much sympathy from his buddies, Magnum just hands his coffee mug to Higgins and bolts off to go meet Karen. If you look at Roger E. Mosley face when he says "Hey Thomas, Higgins said we don't have t...", the audio is dubbed and does not match his lips' movements. (00:07:00)
Continuity mistake: After his first encounter with the annoying reporter, Magnum is swimming. He is wearing blue swim trunks. The he emerges from water to get his towel and chat with Higgins...but his swim trunks are now light brown. (00:14:10)