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: Just as Jacob enters Bella's room through the window, a stunt prop - white band on his right wrist - is briefly visible.
Suggested correction: There is nothing on his hand if you watch frame by frame.
Revealing mistake: When the old couple who give Wolverine clothes are first driving towards their house, there is an aerial shot of them driving over a bridge. This is supposed to be set in Canada (drive on the right) but it was filmed in New Zealand (drive on the left). They are driving on the right but the arrow on the road is on the left side.
Revealing mistake: During the final confrontation in Veidt's lair, you see the actor Billy Crudup in his SFX suit reflected in Nite Owl's goggles, not the image of Dr. Manhattan.
Revealing mistake: After Chuck steps on the toy duck, he looks up to see the alien family and their house behind them. However, there is no reflection of this on his visor, just an empty field and the trees beyond.
Revealing mistake: In the shot right before Coraline finds the hidden door for the first time, she says "Alright Little Me, where are you hiding?" and drops her notebook and pen on the floor. When the notebook and pen are falling, you can see the wires that were used to suspend them while they were being animated. It's a common stop motion technique, but these days they usually try to paint the wires out afterward. It's a pretty severe dutch angle though, and they're only visible for a few frames, so it's easy to miss. (01:27:55)
Revealing mistake: When Helvetica is on the rocket bike, her hair doesn't move.
Revealing mistake: Just after the submarine crew see all the whales passing them by, the shot switches back to the helicopter and all the dials on the console. If you look closely, you can see that the image has been flipped as all the words and numbers are the wrong way around. (00:05:20)
Revealing mistake: During the scene where the four Ninjas dressed in black have a pillow fight with the 'Girl' Ninja dressed in white, you can see that it's not the little girl fighting them, but a tall 'Oriental Man' stunt double instead.
Revealing mistake: During the scene when Scrooge is sitting in his armchair by the fire, the animation of the fire is badly looped and you can see it flickering as it finishes a cycle.
Revealing mistake: When Julie is trapped in the bathroom with the "ghost girl" she is saved when some other girls come in and switch on the lights. However, if you watch the girl who flicks the light switches you can see the switches are already in the "on" position (pointed upwards) and she simply mimes flicking them up. (00:26:47)
Revealing mistake: The movie shows in Matrix-esque slo-mo the double baton swing Goku dodges, from Fuller and his goon. They are nowhere near hitting each other, and yet, this missed baseball-bat swing causes them to KO each other in close-up. (00:16:55)
Revealing mistake: When Steven Seagal makes his triumphant entrance in the credits, his sword misses the first zombie he supposedly hacks (right after "Written by"), by a mile. (00:03:20)