All Roads Lead to Floyd - S1-E13
Revealing mistake: After the shootout at the Ponzi scheme party, Floyd drives his prehistoric Honda in traffic with Magnum at his side. "Magnum" does not have his moustache - it's just some big guy in a Hawaiian shirt they put there as body double without even a fake stache. (00:25:00)
All Roads Lead to Floyd - S1-E13
Revealing mistake: When Bull pushes Magnum against a shelf during the final fight, the stuntman with a thin stage 'stache is seen. (00:44:50)
All Roads Lead to Floyd - S1-E13
Revealing mistake: While Magnum is a passenger in Floyd's car, in the closeups of both of them with Floyd at the steering wheel, there is black cloth over the door beside Floyd (presumably covering the device that secures the side camera to the door), which does not exist in wide shots.
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)
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: In the night shootout, Magnum cocks his pistol in a close-up that is obvious performed by a trained stunt double. Whoever is doing this is wearing the same clothes Magnum has but with the T-shirt in pristine condition straight from the washing machine, while Tom Selleck just took a dive in the dirt. Moreover, he wears the team ring upside-down. (00:22:50)
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: 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: 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: In Magnum's close-up as he looks at The Black Orchid, the scar prosthesis has a visible contour. (00:05:30)
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: Rene cleverly avoids the trap; he turns the wheel to the left, but the car swerves to the right. (00:02:10)
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: 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)