Continuity mistake: When Magnum and JL escape from Thompson's yacht, Magnum's black dress shoes become flat rubber bottomed shoes when the duo climb the rocky hills. Later, when he hears the chopper he puts on the dress shoes, then it reverts back to the other shoes again. (00:24:15 - 00:33:35)
Visible crew/equipment: When Magnum and JL climb the island's rocky hill so they can set up the transmitter as high as possible, just as JL shouts, "and give you an hour's head start," a crew member with his clipboard are visible at the right side/corner of the screen. (00:25:15)
Visible crew/equipment: While Higgins, TC, and Rick are getting tanked, Higgins tells the others he doesn't think Magnum is dead, then when Higgins gets up he walks over to the lamp and the actor's white tape mark is visible on the rug. (00:27:40)
Continuity mistake: When a drunk Rick flops on the couch, his belly has a big wet patch, but the shirt was fine when he poked Higgins with his finger disputing the command of the operation. (00:28:15)
Other mistake: Magnum lights up a signal fire for TC. It is supposed then to raise significant smoke (which Rick spots) in a short time, but when we see the fire, it's not generating visible smoke. Moreover, Magnum uses fuel to light it up, but they are supposedly out of gas and had to paddle for a long while before getting to the island, so it's odd that they'd suddenly have spare fuel for that predicament the day after. (00:38:45)
Revealing mistake: When TC, Rick, and Higgins rescue Magnum and JL in the chopper, TC is wearing a short sleeve light blue tee shirt, but once they take off with Magnum hanging onto the side of the chopper, in Magnum's closeup TC is wearing a yellow tee shirt. Also note, the pilot in this shot is wearing dark brown spandex-type long sleeves under his short sleeved yellow tee shirt, to give the appearance of being the same skin color as TC. (00:39:20)
Revealing mistake: To board the helicopter as it takes off is a stunt double with a bulkier core than Tom Selleck's and lighter brown hair. (00:39:25)
Factual error: Magnum shoots a flare gun at a helicopter, and that brings it down making the heli's engine sputter and slowly lose altitude. That's Hollywood nonsense, as a projectile of that kind wouldn't do that sort of damage. (00:41:00)
Visible crew/equipment: Near the end, while Magnum is standing by the hospital window JL is giving him a rundown of her personal history, and the shadow of the moving boom mic is visible on the curtain at the top, right side of the screen. (00:44:45)
Continuity mistake: When Magnum tackles the 'commando' from behind coming off the wall, the elder guy with the white beret is holding both hands on the right armrest of the chair. New shot and he has just a hand on the other one. (00:03:25)
Continuity mistake: Inside the study, Higgins is having Zeus and Apollo bite the dog handler. In the background, William B. Knox stands behind the armchair with his right hand over the left. The hands have instantly traded places in the next shot. (00:04:40)
Continuity mistake: The lads greet Magnum growling at him. They pass by a table with a flower centerpiece on it. A minute later, the producer gives him the thumbs up as he walks out, saying "Welcome aboard"; the table gets back in frame, and now the flowers are gone and all there's left is a decorative plate. (00:05:15 - 00:06:55)
Continuity mistake: Magnum and Rick by the wall are looking at Jack Martin going back to his trailer. They are on a spot in the sun and have plenty rays on them, but in the rest of their exchange with a very bored TC they all are in the shadow. (00:13:00)
Continuity mistake: Higgins introduces Lt. Tanaka with a hand gesture in close-up he showed no sign of doing in the previous shot - in fact he had that hand down, planted on the desk. (00:16:45)
Other mistake: Olivia Ross crushes in anger the paper cup she was drinking coffee from - and she does not wet her hand or stain her perfect white dress doing so. (00:23:25)
Continuity mistake: Searching the trailer, Magnum tells his friends the suicide theory. Rick in close-up is holding the flashlight in the same left hand he is leaning against the drawers with, but it is in his right hand at the cut. (00:38:50)
Visible crew/equipment: When Olivia thanks Magnum for his help Higgins walks over and tells her the hospital called, then right after Higgins says, "He appears to be improving," the tip of the moving boom mic dips into view over Higgins, at the top of the screen. (00:42:25)
Continuity mistake: By the deathbed of her husband, Olivia Ross asks, startled by Magnum "What are you doing here?" Her right arm position changes (along the railing or not) depending on the camera angle. (00:45:35)
Plot hole: With the murder happening literally on tape, it's quite extraordinary and inexplicable that the police did not acquire the footage as evidence, especially with film buff Lieutenant Tanaka investigating, who is not fooled by the culprit's act. The footage would have been used for insurance reasons as well, and instead it is reduced to some novelty everyone checks out just to fight boredom on an evening at the estate.
Continuity mistake: The director, Myrt Callahan, is talking to the producer while Higgins is on the phone with Robin Masters. Knox says that people can grieve and work at the same time, and she has both arms forward, but in the background when the camera focus is on Higgins we see her right hand on her waist.
