Visible crew/equipment: When Higgins goes after the tow truck towing the Audi, it then cuts to Magnum pulling up to Maynard's trailer, and the reflection of crew, lighting, and equipment are visible on the surface of the Ferrari. (00:09:25)
Other mistake: Rick and TC are at the counter of the Chinese joint when they hear a bang and a car speeding off. The noises are almost simultaneous, which means the lone assailant exploded a gunshot from their car while they were at the wheel. Uncanny coordination, recovery time and reflexes, contrary to the parking custodian in a booth we see there, who reacts to the car passing by, but was unfazed and with their back turned after a shotgun has been supposedly been fired meters away from him. (00:28:25)
Audio problem: When Higgins lists the various things he expects to run into when he enters' Magnum mancave, there's a noticeable difference in the ambience of the audio when it cuts to Magnum as he mentions the "soiled garments."
Continuity mistake: Magnum pours champagne for Miss Elizabeth Barrett, and finishes the bottle. The cloth around the bottle falls off, but it's neatly arranged around it again in the wide shot that follows the reaction shot on Higgins. (00:14:05)
Visible crew/equipment: When Tom Selleck's wife is driving off at the end of the episode, equipment and lights are reflected in the side of the car. (00:47:30)
Revealing mistake: In the aerial shot of the helicopter signaling the death of Merlin, its registration numbers are mirrored. (00:45:15)
Factual error: Higgins frightens the parrot with his peregrine falcon call, and the parrot flies away. The sky is a fairly big place though, and TC's helicopter is far away, so the fact that it'd be sucked in (that's not how helicopters work), maimed and somehow explode in a puff of (clean) feathers that instantly and calmly float down is borderline cartoon slapstick. (00:45:20)
Revealing mistake: In the Birdemic-like scene when Magnum barely escapes with his life from a deadly parrot before Higgins squeals it into suicide, our hero has multiple bleeding from lacerations on his arms that disappear one shot later, leaving room to face laceration who disappear in the following scene. (00:45:15)
Continuity mistake: Emily reaches the end of the road and stops the Robin-3. The parrot climbs on her arm, the part above her elbow, but when she steps out he is on her forearm. (00:38:40)
Continuity mistake: After dinner and much champagne, Elizabeth Barrett is in the study. In close-up she puts to the side a page while she checks the left; in the following one the right hand, holding the page, is hovering. (00:15:40)
Continuity mistake: When Elizabeth tells Higgins that she'll be working nights in 'his' study and they may jog together, she holds the champagne bottle with a hand wrapped around its neck at a distance from the rim that varies between shots. (00:11:45)
Continuity mistake: Higgins is speaking with Robin's former teacher at the airport; she has her index finger outstretched in front views, curled in the respective reverse shots. (00:08:30)
Continuity mistake: A puzzled Higgins spots the drunk and disorderly Elizabeth Barrett sitting on the cart, champagne in hand. He greets her; when he states his actual name dispelling any rumor of him being a seagull, you can see a woman with a very colourful (rainbow, in fact) sweater walk behind him. The same woman passes another time, and is also at the conveyor belt, opposite side of the hall. (00:07:40)