Revealing mistake: When Woody falls out of the closet wrapped in the string lights he hears Buzz's voice, and in the next shot as Woody sneaks up to Hannah's room we see Sid's open door and doorway, which looks perfectly normal. However, after Woody rescues Buzz from Hannah's tea party they both stop in the hallway, and there's another shot of Sid's open door and doorway, only this time it's not normal to say the least. Five of the six hasps, bolts, and locks that should be (and normally are) screwed into and attached to the inside of Sid's door (one hasp mechanism, third one down from the top, is attached to the door's frame) are now actually kind of floating there in mid-air right beside the doorway, as if there's an invisible door there. Weird that Pixar artists deliberately did this, but it's bizarrely funny to see.
Continuity mistake: Carl's cop car has the licence plate "G2298" which is printed thinly on the licence plate. Then, when the vine wraps around his car, and bends it in two, the licence plate is now "CFJB95", printed very boldly on the plate. The words "POLICE 004" also differ, as does the bumper and the lights. Totally new car, methinks... (01:14:55)
Revealing mistake: When the plane first lands at Bangor airport, the words 'American Pride' on the plane are reversed, like they are reflected in a mirror in one shot as its wheels hits the runway. (00:50:55)
Continuity mistake: When Godfather Drosselmeier walks into Marie's bedroom before he tells her the story, the bedroom door opens from the left, but after Marie's mother brings her the breakfast tray the door now opens the opposite way, from the right.
Continuity mistake: When Lucifer confronts Thomas, Lucifer forcefully pulls him closer and puts his right hand on his chest, but the close-up shows that his hand is under Thomas' arm. (01:21:20)
Continuity mistake: When Omri opens his birthday presents, Gilly's rat in the plastic ball is on the table; two seconds later it disappears.