Continuity mistake: A UFO crash lands in Canada and sits amidst trees in a wooded area. Just before the craft explodes, the only snow visible is on mountains in the distant background. After it explodes, however, the ground and trees all around it are suddenly covered with snow. (00:36:30)
Revealing mistake: In the interior shots of Mobile 1's cockpit, we see that there's a crew of 3 and that the pilot is black. But in shots of the exterior (miniature model stock footage), there's only one occupant, a pilot, and it's a doll with distinctively Caucasian features. (00:26:30)
Plot hole: The alien-possessed Mason steals Captain Lauritzen's fingerprints by pressing his fingertips to the captain's and "heat transferring" the prints. Big problems here: those prints would now be backwards and for the wrong hand. But when the computer later reads the prints, it fails to notice this and passes him through security as "Identity Correct." (00:23:30)
Revealing mistake: In this episode the aliens with the help of 'turncoat' Turner have frozen a moment in time in which they will attack and destroy SHADO HQ. Everything and everyone is frozen in place - except for the guy in the background walking across the road during Straker's and Turner's 'car' chase in the 'Harlington/Straker' go carts.
Revealing mistake: While Straker, Foster and Dr. Jackson are standing over Catherine's body at the end, the "dead" woman's eyelids are twitching. (00:46:30)
Revealing mistake: Another piece of stock footage used throughout the series was a shot of the shiny metal sign for Harlington-Straker Studios. The clock on the side of a building is reflected in the sign's surface, always showing the same time of day - so it's 1:50 every time Straker drives by. (00:24:00)
Continuity mistake: When Straker grabs the gun from Foster, we can see a man in a spacesuit outside Moon Base's control room window. But in an establishing shot just before this, we saw an exterior shot of the base, including that window, and the spacesuited man was nowhere in sight. (00:30:00)
Revealing mistake: Straker and Foster take off for the moon in a large red hovercraft which, even though it's launching in broad daylight, doesn't cast any shadow. (00:12:00)
The Responsibility Seat - S1-E25
Factual error: Moon Base is imperiled by a rogue Russian mining trawler said to be heading "straight for it." But several shots of the vehicle show it veering wildly in very wide arcs, moving far too erratically to determine that it's on a collision course. (00:38:00)
Flight Path - S1-E15
Revealing mistake: When the mobile-units leave the transport carrier, you can see that both are being "driven" by dolls. (00:22:00)
Continuity mistake: In the opening scenes, the smudges and rips in Straker's black shirt keep appearing, disappearing and changing configurations between shots as he races through S.H.A.D.O. HQ and the Harlington-Straker studio lot. (00:04:30)
Deliberate mistake: For reasons unknown and unexplainable, the otherwise spacious and well-equipped Moonbase has halls and doorways too short for the average human to fit through without ducking. (00:20:00)
Revealing mistake: Due to re-used special effects footage, the submersible Sky One fighter, whenever it launched from the ocean at night, always took off under a full moon. (00:07:50)