Visible crew/equipment: A boom microphone is reflected in Luke's goggles when he says "Hey, what's the matter? You smell something?"
Factual error: At the climax of the movie, Alice swings the machete at Mrs. Voorhees and decapitates her. When the blade makes contact with Mrs. Voorhees' neck, her head flies off at an incorrect angle, as though the cut began on the opposite side.
Continuity mistake: While breaking down the bathroom door with the axe, Jack repeatedly strikes and damages the right hand panel, but as he turns away from the door (when he hears the snow-cat) both left and right panels have been damaged.
Factual error: The first thing on screen after the opening credits is the year the film is set in, 1953. How then, do Kim Novak and Tony Curtis make their arrival in a Cadillac convertible, which is quite obviously of 1959 vintage? (00:19:44)
Deliberate mistake: Has there ever been a more obvious body double than the one used for Angie Dickinson in the shower scene? Not only does the top of every shot stop right at the collarbones, she is much taller than Dickinson, she has a much deeper tan and (of course) her breasts are much, much bigger. In fact that is Victoria Johnson, Penthouse Pet of the Month for August, 1976.
Continuity mistake: When the windows on Nick's truck are smashed, Elizabeth has protective gloves on when she covers her face from the glass, they are then gone when the truck comes to a halt.
Other mistake: At the end of the movie where they are looking at the headstone of Jake Hobart, the date on the bottom of the stone is April 3 1913, despite dying shortly before the Titanic sank in 1912.
Continuity mistake: The egg timer in the jail is about to run out, but when Dale runs over to it and tries to turn it over, there is more sand in it than before.
Visible crew/equipment: When Harris and the two Irish men have been killed at the end and the car crashes on top of the other the ramp used to make it fly is visible.
Factual error: A film about the making of a film. A car is filmed going off a bridge, and the footage is played back repeatedly. Throughout, the car is referred to as a Duesenberg, even though, in nearly every shot, the Mercedes tri-sected circle logo is visible above the radiator.
Audio problem: When Benson is dismantling Hector and putting his brain in the container, he says 'What you can't stand, you run from,' but his lips don't match what he says. (00:48:50)
Continuity mistake: When Julian Kay is tearing apart his Mercedes to look for the stolen jewels, he is seen pulling some plastic off the driver's door, in the next shot, you can still see the plastic attached to the car door.
Visible crew/equipment: When John is playing the piano, after the door opens by itself in the music room, there is a shot that revolves around him. If you look in the large mirror in front of the piano you can see the pole of the boom microphone reflected (behind the chandelier). (00:19:21)
Revealing mistake: In this very-low-budget but star-studded flick about UFO contactees and cattle mutilations, Jan Michael Vincent's semi-auto handgun runs out of ammo during a firefight after firing only 3 rounds (the slide locks open, indicating the magazine is empty). Without reloading or racking the slide, Vincent continues firing 5 more rounds; but we see again, in close-up, that the slide is locked open, indicating an empty magazine. (01:00:55)
Visible crew/equipment: When the survivors of the cruise liner sinking approach the ominous ship, it's supposed to be deserted, but as a window opens, a person's arm holding a stick to open the window is visible.
Revealing mistake: At the end of the film, it's obvious the ground that Phil falls into is just some mats dressed up in fake snow.