Revealing mistake: During the kendo sparring, on the breastplate of the kendogu you can see the reflection of the set lights, practically all the time. (00:11:00)
Revealing mistake: When the guy tricked by Magnum gets out of the car, check out of the very right side of the frame. You can actually see the hand of one crew member releasing the garage jack's lock, so that, when the car is kicked, the relatively light impact is enough to release the hydraulic lift and make the car comically bounce back on the ground. (00:15:25)
Revealing mistake: Magnum manages to shake off the 'government guy' by putting his car on a jack while Babs provides a distraction. But if you check the moment when the guy gets on the car, the back wheels are in frame and not at all off the ground as the clever ruse needs them to be. (00:14:40)
Revealing mistake: During the jogging phase, which may not be hazardous but surely is defatigating, Tom Selleck is replaced consistently and noticeably (except the close-ups, of course) by his stunt double Tom Lupo. (00:40:35)
Revealing mistake: Magnum neutralizes the pursuer at the gas station jacking his car. In the close-up of the wheels spinning with no traction and then stopping, the hubcap is in pristine condition, but in the next one, it sports a dent already from a previous take. (00:15:20)
Revealing mistake: Magnum is carrying up the mountain stairway a Higgins-shaped dummy instead of the real John Hillerman, as obvious by the lifeless bounce of its legs. (00:38:20)
Revealing mistake: Rene cleverly avoids the trap; he turns the wheel to the left, but the car swerves to the right. (00:02:10)
Revealing mistake: The moment Magnum hops on the Ferrari ending the brawl on the beach with the two goons in ski masks, parallel to the tire tracks in the sand you can see others from a previous take. (00:23:25)
Revealing mistake: In Magnum's close-up as he looks at The Black Orchid, the scar prosthesis has a visible contour. (00:05:30)
Revealing mistake: After Magnum gets punched by Ted Danson, he drives off. Oddly enough, he drives by TC's van, parked in front of one of the villas of the area, and that has no business being there. (00:24:05)
Revealing mistake: Mrs. Kimball falls off the wheelchair in an alternative take, featuring a stuntperson instead of the elder actress. Problem is, the stuntperson is barefoot, and Mercedes McCambridge wears socks and slippers. (00:05:50)
Revealing mistake: When Agatha Kimball gets her wheelchair caught in a gap between the step and the ramp, stagehands can be seen as they safely hold Mercedes McCambridge to avoid her getting hurt. (00:05:45)
Revealing mistake: When the bandit holds Adelaide and then drops her off the horse, you can get a good look at the face of the person, and it's a younger stuntwoman, not Christine Belford. That stuntwoman has to roll in the dirt and get up, but Christine Belford emerges in the next shot without a speck of dirt on her shirt's sleeves nor the back of the jeans that got all soiled earlier. (00:14:45)
Revealing mistake: Magnum and Adelaide are headed to her place on TC's chopper. Throughout the sequence, the camera moves up and down but can't conceal that the fact that they are not moving at all and they are just sitting in the chopper, with set lights reflected in her glasses and even the silhouette of the rotor of the chopper, completely still, peeking through the glass. (00:04:50)
