Revealing mistake: When the Wicked Witch scares the Munchkins in Munchkinland, where Dorothy lands, she disappears into a cloud of smoke she creates. But you can see her sneak down into a trap door below. [As a sidenote to this entry, Margaret Hamilton was hospitalized for severe burns after a take of this shot (not the final one used) when the stage elevator got stuck and the explosion went off.] (00:30:45)
Revealing mistake: Just after Harry attacks Snape at the Shrieking Shack, he insists on knowing about Peter Pettigrew. In the next shot, as Lupin says, "He was at school with us. We thought he was our friend," there are wedges under the wheels of the piano, however, in the following shots they're gone. (01:34:10)
Revealing mistake: When Qui-Gon, Jar-Jar, and Padme are eating at Anakin's house, Anakin's mum pours water for Qui-Gon. But when she gets to Jar-Jar, she tips the pitcher but no water comes out. (00:39:10)
Revealing mistake: When Captain Needa is killed by Darth Vader because they lost track of the Millennium Falcon, in the background, two guards come to take him away. You can clearly see the dead captain get up almost by himself. (01:10:50)
Revealing mistake: It's painfully apparent that the actors are hung on wires pretending to swim while outside the sub.
Revealing mistake: A horse gallops through a field and you can see a telephone pole.
Revealing mistake: In the early part of the film, Beverly D'Angelo and Chevy Chase check into the hotel/motel. She goes in to take a shower but he barges in. If you look real closely, she is wearing underpants and is not nude although she is taking a shower.
Revealing mistake: When Michael Douglas attempts to swing on a vine over a deep abyss, the rock that he runs into on the other side moves like a marshmallow, indicating that it's a fake rock. (00:39:10)
Revealing mistake: In the scene where Doc Brown is following Biff into the tunnel, as Marty starts to pass between the cars on his hoverboard, one of the wheels on the rig supporting the hovering DeLorean is visible. (01:30:30)
Revealing mistake: In the end when Mulder is reading the paper in the park. The paper is clearly a prop. Only the frontpage is real - when he puts the paper away you can see that the rest of the paper consists of blank pages. (01:45:45)
Revealing mistake: It is not what is seen here that is the problem, but what we don't see on the Hogwarts Express; first on the way to Hogwarts when Harry, Ron, and Hermione are in their compartment talking about Draco, and second, during holiday break, when Harry and Ron are talking about Unbreakable Vows. As the camera faces the large compartment window, we see the scenery out the window, but as the train speeds along, the scenic reflection of the windows opposite it, in the corridor, should be seen but isn't. What is reflected is the light colored wall of the compartment beneath the blacked-out window. The camera filming the shots from this angle is positioned at that window, and to hide the camera/crews' outline, the window was covered.
Revealing mistake: The road leading out of the samurai village has distinct tire tracks from vehicles.
Revealing mistake: Near the end of the movie when everyone except for Peter dies. Lucy is supposed to be dead, but we can still see her breathing.
Revealing mistake: When the bridge is exploding from the mine attack, the stuntman playing Jason obviously launches himself out of the captain's chair.
Revealing mistake: As the Predator tends to his wounded leg, one of his claws can be seen bending as if made of rubber.
Revealing mistake: After Nuclear Man destroys the cab's hood, the shot changes and there's a thick string running behind him all along the car, and the cab driver is stretching out to pull it. Probably he was activating some sort of bad FX.
Revealing mistake: After Jim's horse is shot from under him while running down the really steep hill, and Jim later regains consciousness, before he turns and finds his horse dead, if you watch closely you can see the horse still breathing.
Revealing mistake: When the Enterprise is leaving its docking station and pulling out, two little bugs or debris from the model lands on the camera lens on the lower left corner (corrected in the Director's Edition).
Revealing mistake: In the major helicopter scene when Ride of the Valkyries is played, the actual tape isn't going over the playing heads. (00:37:29)
Revealing mistake: Aboard the Hogwarts Express, when Harry stands beside the open window and sends Hedwig off with the letter for Sirius, surely his hair and clothes would be wildly moving about, because of the strong wind from the fast moving train.