Factual error: Magnum takes part to an Ironman triathlon contest, but the writers did not bother to follow the correct order of the parts of the race, which would be swim, bike, and then run. Here he cycles last.
Factual error: Magnum is scouting the prison facility with his binoculars. During the scene, the audio track to give the impression of the jungle surround has the trademark kookaburra laughter, which is not a Hawaiian bird. (00:33:55)
Factual error: Just before the fade-out of the first shot of Robin's limo in France, there are 3 street signs saying "Meyrargues 5 kms", "Marseilles 22 kms", "Aix-en-Provence 6 kms." It's an impossible triangulation; they are almost on a line, Marseilles is about 40 kms south of Aix, which is about 18 kms south of Meyrargues. (00:01:40)
All Roads Lead to Floyd - S1-E13
Factual error: When Floyd is standing by the Cadillac with the vanity FLOWER license plate, on the same plate you can see in the upper right corner that its registration sticker on the license plate is a 76 one. For being a fancy car by a posh golf course, it's quite odd to be 5 years in arrears of the tax - it is, viceversa, a mistake that happens in other car props during the season. (00:04:15)
Factual error: Justice in Hawaii works at a breakneck pace; TC is jailed and goes on trial instantly, which is fine, but also his impounded chopper goes for auction within a couple hours as well.
The Ugliest Dog in Hawaii - S1-E8
Factual error: Wheels stuck in the jungle terrain, the mobsters get out of the car. It's a jungle in Hawaii, but, lo and behold, the first sound they hear is the call of a kookaburra, which is native of Australia and New Guinea (but also one of Hollywood's favourite stock sounds). (00:25:05)
Factual error: For the ballistic test, Higgins goes on to explain in great length that the shell contains 12 pellets, but when he displays the effect on the second target, it's blatant that there are way more than 12 holes in it - and the way the test is done, it is specified that it is the result of a single shell being fired. Incidentally, there are also more pellets than what Higgins states when he empties the shell initially -14 instead of 12 - but this last detail realistically can be assessed only if you pause. (00:29:20)
Don't Eat the Snow in Hawaii - S1-E1
Factual error: Magnum manages to lure the dogs outside making them wail in pain as he plays a sound that greatly bothers them. As great and sensitive as dog hearing is, Magnum put in the sand past the perimeter wall of the mansion a little Sony Micro cassette recorder M-202 and played the sound off its in-built speaker. That would hardly produce, especially at that distance, an output worth the kind of reaction displayed here.
Don't Eat the Snow in Hawaii - S1-E1
Factual error: Magnum phones Rick at his Casablanca-like establishment and tells him; "Two guys tried to run me off the Pali Highway. They deep-sixed about a mile past Lanai Lookout." Lanai Lookout is not on the Pali Hwy, it's 15 miles driving south off the east end of the highway, and Magnum was in the Nu'uanu part. (00:40:35)
Factual error: When Magnum looks at the collection of tapes and books from Erin, the shelves are stocked entirely with tapes marked L-250, L-500, L-750. A huge collection...for Betamax, but Erin's VHR player is a VHS, as shown by the logo in close-ups. And in fact, Magnum to watch her movie puts in close-up a T-120 tape in the machine, which is the proper format. (00:21:15)
Factual error: The villain holds Magnum at gunpoint with a weapon with a silencer. Which is useless, the gun being a revolver. (00:41:20)
Factual error: Richard Johnson appears in the end credits as "Brigadier General Alistair Ffolkes, Royal Army", and is consistently referred to that way by Higgins and Hooker. The rank was abolished in 1921, the Royal Army would have him as as a Brigadier or a higher rank.
