Revealing mistake: When Ripley is leaving New York, there is the shot of the ship sailing out of the harbour. Check out the water - one layer has been 'cloned' on top of another.
Revealing mistake: When the Japanese tanks are firing upon Godzilla, one of the pyro effects catches the Godzilla suit on fire (at the arm). One can see the stunt man begin to frantically shake his arm upon this realization before the editing cuts to another shot.
Revealing mistake: During the catamaran sailing scene, the boat jibes and Brosnan leaps across the trampoline and starts grinding on an empty winch, with no line in it. (00:37:40)
Revealing mistake: When the Headless Horseman is about to kiss Catrina's stepmother, you can see his actual teeth behind the filed ones. Christopher Walken's teeth are blacked out and their outline is visible against his tongue during the closeup of his face. (01:37:20)
Revealing mistake: During Bartleby's "Prepare to taste God's wrath" diatribe, you can clearly see the seam along the front of his shirt that he uses to tear his shirt open revealing his armour. This seam is not seen at any other point in the movie.
Revealing mistake: At the end when Charlie Sheen is balding you see the edge of the silicone wig in the middle of his forehead. (01:41:05)
Revealing mistake: When the Interceptor team flies in their cargo plane to Mexico to investigate the UFO crash, several shots filmed from the front show the six of them all in the cockpit (not in the body of the plane.) They're seated as they might be in a car, three across, front and back. The window of the cockpit looks remarkably similar to a station wagon windshield, down to the large rectangular front windshield, and even the rear view mirror is in place.
Revealing mistake: In the scene where Will Smith first jumps aboard the rear of Loveless's train, as he climbs onto the roof of it you can see contrails from a jet aeroplane in the sky (top left).
Revealing mistake: When all four of the guys are driving the Volvo through Detroit, if you watch real close, sometimes you can see 1980's and 90's vehicles parked on the side of the roads. Especially when they show a long shot with an older mustang following them, there is what looks like (it's hard to tell) a newer Buick or Chrysler (like the 300m) on the left side of the screen.
Revealing mistake: When Jamie Lee Curtis falls into the fuel tanks, how could she be breathing? The gases would be too toxic for her to breath, and wouldn't she be blinded by the fuel?
Revealing mistake: When Whiplash is in the cave and Dudley comes and checks it out, the cave falls in. You can see a black curtain fall down while the screen goes black.
Revealing mistake: In the scene where they are all having a farewell dinner at Tony's restaurant. At the end of the meal they are all scattered around the restaurant, the camera is on Bella and Honey and in the background, outside the restaurant, 4 extras walk past, 3 at the front and one behind. The next shot is at the window where Max and William are sat, again the 4 extras walk past in exactly the same order and positions. They are the same people because one of them has a pink top on and you see that twice.
Revealing mistake: When Plunkett and Macleane emerge from prison they walk through a gap between a woman cooking and a circle of people around some men fighting, Macleane first, followed by Plunkett. As Plunkett passes through the gap he kicks a basket over and a blue gas cylinder with an orange pipe rolls out from underneath.
Revealing mistake: During the prom scene, especially during the song "(Don't You) Forget About Me", none of the band guys (especially the older man keyboard player) are actually playing their instruments.
Revealing mistake: When Kit Ramsey shoots at the drums set, you can see the explosive charges on the cymbals.
Revealing mistake: When Claire jumps down into the silo filled with apples, the whole top layer of apples bounces, which indicates that there is only a thin layer of apples instead of apples all of the way down. Soft material would have been under the apples during filming. Rotting apples wouldn't have that sort of give normally.
Revealing mistake: When Yoichi's mother is killed, the blood coming from her body is very obviously just colored water, as it is too bright and too thin to really look like blood.
Revealing mistake: In several scenes (e.g. in the deli & in the tunnel, at the end) the ice cubes used to cool Elvis down are obviously not real ice.
Revealing mistake: When the man accidentally coats his hand in breading and cooks it in the boiling oil, you can tell his hand has not been damaged at all. The breading on the outside is just a little cooked, but his skin underneath seems perfect.
Revealing mistake: The same extras can be seen in several different crowd scenes. Specifically, the same people can be seen in the crowd that storms the computer fair and in the auditorium when Steve Jobs makes his final speech.