Continuity mistake: In the shot of the alien's tail wrapping around the back of Lambert's legs right before it kills her, the floor is different to what it was before, there is water suddenly falling from the ceiling when there wasn't before and her trousers have changed from white to blue. This is because that shot was originally intended to be used when Brett was killed.
Visible crew/equipment: You can see the string that pulls Bubba off the bike when Max shoots him. (01:19:41)
Continuity mistake: In the final scene on the bridge, Spock and McCoy are wearing coloured arm bands which identify their departments: Spock's is orange (for Science) and McCoy's is green (for Medical). In the very last shot, Spock is wearing the green band and McCoy is wearing the orange one (corrected in the 2022 re-release of the Director's Edition).
Factual error: Although it's already been mentioned that the scene of the shuttle being stolen from the back of the 747 is impossible because the shuttle wouldn't be fueled while being transported, it should also be noted that even if the shuttle was fueled, it would still be just as impossible. During the getaway, the thieves ignited the shuttle's three main engines to get free of the 747 and escape. The thing is, the shuttle's main engines are fueled entirely by the large external tank the shuttle and the solid fuel boosters are attached to during liftoff, and once the tank is jettisoned, these engines cannot be used. The only engines the shuttle's internal fuel feeds are the reaction control thrusters and the Orbital Maneuvering System (which are the two smaller engines located in the bulges just above the main engines). Both the RCS thrusters and OMS engines are almost totally useless within the atmosphere, so even if the thieves managed to get the shuttle free of the 747, they could only get it as far as it would glide unpowered. In fact, they could probably get it further if it wasn't fueled. It should be noted that this is not a fictional, futuristic spacecraft. It's a bog standard shuttle, stolen from NASA, on the back of the modified 747 used by them to transport the orbiter from its landing site to Cape Canaveral.
Continuity mistake: In the beginning, when Mike and Jody raise the hood on the car, Jody's hand holding on to the hood alternates between his right and left hand over three shots. (00:13:10)
Plot hole: When Jack The Ripper checks his watch before confronting H.G. Wells and demanding the key, the hands point to 8:50, the ensuing chase to the museum and demise of the Ripper may have used up a half hour or so, yet the time on the wall clock indicates that it is midnight.
Suggested correction: Movie time and real time don't match, so 3 hours has passed without all 3 hours being shown. The fact that the clock now shows midnight is meant to explain this fact without the need for subtitles to reveal the time.
Factual error: In the PALOMINO scenes, Anthony Perkins wears a long lab coat. In most of the scenes, it hangs straight down; but in the low gravity aboard the ship it should be flattering about (that's why such loose garments are not worn by real-life cosmonauts; they would be a hindrance).
Factual error: When Mission Control talks with Challenger 2, the Spacecraft's camera feeds of the Crew are displayed up on two wall-sized TV screens. Between them is the familiar Mercator map of Earth with the ground track of a low-orbiting satellite superimposed. Challenger is nowhere near low orbit: it's out past Mars, in the Asteroid Belt. The middle screen would have a schematic of the ship's interplanetary path.
Factual error: Buck Rogers is supposed to be a Captain in the Air Force, but he is wearing Navy wings. In fact he is not even wearing Naval Aviator (pilot) wings, he is wearing Naval Flight Officer (navigator) wings.
Visible crew/equipment: Set lights and shadows of seemingly team members and filming equipment are reflected on the Captain's helmet throughout the film.
Other mistake: When showing the animals outside of the cabin, the shot of the deer is obviously stock footage. The video quality doesn't match the rest of the movie. (00:28:40)