Continuity mistake: When Snake kills the wrestler he falls forward shoulders forward, next minute his arms are over the ropes, next minute his arms are in a different position again - quite active for a dead man. (01:16:55 - 01:18:10)
Continuity mistake: When Indy is distracted by the young girl and her eyelid message, the girl changes from a window seat to another row when the bell rings to end class.
Continuity mistake: When Cheryl is running through the woods, she is wearing slippers that stay on up until she reaches the cabin door. However, in following shots, she is shown barefoot, and when Ash opens the door her foot is dirty as if she'd been running barefoot the whole time. (00:28:05 - 00:29:10)
Continuity mistake: The buttons on Amos Slade's shirt repeatedly change sides between shots throughout the movie. One example is while Copper and Tod are swimming, when Amos tells Chief that Copper has strayed off again, the buttons on Slade's shirt go from being on the left to being on the right, then back to the left again. (00:21:50)
Continuity mistake: After Ben Tramer gets hit by the police car, his body can be seen and heard slumping. In the next shot, he is pinned fully upright.
Factual error: The ship transporting the Great Britain team to France has a marine radar antenna, which did not appear on ships in that decade.
Revealing mistake: Just after the scene where Mark is killed, there's a shot of Jason's feet as he opens a screen door and walks across a dusty hardwood floor. As the dolly pulls backward across the floor, you can see the camera's roller marks in the dust. (00:59:10)
Visible crew/equipment: In the scene where the bad scanner is trying to kill the good one using the telephone line, when the good guy turns it back and blows up the office/lab at the other end, one of the scientists is blown back through the glass by the explosion. In the shot from outside the room, it is easy to see the cable pulling him back. (01:22:55)