Continuity mistake: At the beginning of the film, we see Sully asleep in his bed and the alarm clock/radio on a bedside cabinet to the right. Later, when Boo climbs into Sully's bed, the clock/radio isn't there anymore. (00:04:50 - 00:32:30)
Other mistake: In the scaring simulation room, the alphabet wallpaper border at the top of the wall has the "J" written backwards.
Suggested correction: The walls of the room also have nonsensical drawings like a giraffe with two heads. The implication is that the monsters designing the room didn't entirely know what kids would actually have in rooms (like they didn't know that giraffes don't actually have two heads). So they thought that humans have the J backwards.
Whether or not the backwards J was intentional or as a joke, it would still seem unreasonable for the monsters to get it wrong when you see they got the pictures for each letter seen correct "jaguar", "kangaroo "pig", "quail", "rhino." I would at the very least call it a character mistake.
As the original correction said, it's just an example of the monsters not understanding the human world. Not a mistake.
Yet they know the alphabet? I doubt it.
Continuity mistake: When Mike, Sulley and Boo are walking to the Scare Floor after leaving the locker room, Mike's feet and legs are soaking wet. His feet are suddenly dry by the time they reach the Scare Floor. (00:38:45)
Audio problem: When Mike and Sulley walk through Monstropolis, Mike goes to his car. An automatic unlocking sound from the car, but the keys Mike is shown holding appear to be the keys one would use to manually unlock the door. (00:07:20)
Suggested correction: Monstropolis is shown to have many things that operate differently from the real world. It isn't such a stretch to consider that car keys work differently as well.
Continuity mistake: There is a purple chair and a green chair in Mike and Sulley's apartment. The green chair disappears when they are at the apartment with Boo later. (00:05:45 - 00:27:50)
Suggested correction: Didn't they use the chairs fabric to make Boo's disguise? The chair would have been ruined.
They only used Sulley's chair to make a costume for Boo. Mike has his own chair but we are never shown as to where he keeps the chair. He may have put the chair somewhere else in the apartment so Boo wouldn't her germs all over it.
Other mistake: In the door vault scene, Boo's laughter causes all the red lights on the doors to generate and fully power. Unlike the other two scenes - back at the apartment and the trash compactor - this resulted in a blackout. (01:09:09)
Suggested correction: In the house and at the compactor, it caused an overload. This resulted in a blackout. The doors seem to work differently.
Audio problem: Jerry counts down from seven. When he has to say one his mouth opens, but he doesn't actually say one. (00:14:38)
Suggested correction: Many times when counting down, three-two-one is silent.
Especially when filming something like this, so the numbers aren't accidentally recorded.
Suggested correction: Sully may have unplugged the alarm clock and put it somewhere else, especially when there's a "dangerous" child in his home, and he wouldn't want his things to get contaminated.
This correction is a stretch. If he doesn't want his things contaminated, why not remove the pictures and lamps? Why let her sleep in his bed with his blankets?
Bishop73