Other mistake: In the scene where Bates leaves her motel room to back her car up to the door, he doesn't use keys to start the car.
Other mistake: When Cody stole Barney and was running from Abigail and Marcella he hid in the closet, but the girls thought he went to the attic. When he came out of the closet the door made a creaking noise. If the noise was made when he went in, then the girls would have known he was in the closet rather than thinking he went to the attic.
Other mistake: In the scene where Vir gets in a fight with Zack you can for a moment see the Rolex that Stephen Furst is wearing on his right arm. (01:21:10 - 01:21:20)
Other mistake: Before the job, in the car, Don Cheadle, in the back seat, hands out a hacksaw, a ratchet and a pump-action shotgun, which he pumps before handing it over. The man taking the shotgun immediately pumps it again, which means it's been pumped twice, and a cartridge should have been ejected, but it wasn't. Or the gun's empty, in which case there was no point pumping it once, let alone twice.
Other mistake: When Charlie is helping Jack watch TV through the window, his mother comes in and talks to him. By this point Charlie has stopped changing channels, but we can see the channel change effect once more.
Other mistake: Towards the end of the film, when the girls have locked themselves in the school, and Odette addresses the girls about voting what they feel, Tinka and Tweety hand out the ballots. When Odette says "You think times have changed, and we go our own way...", we see the camera focus on a group of girls. Now if you look closely at the middle row, at the girl on the right, you won't be wrong if you think that that's Kirsten Dunst. What's wrong with her being in the picture? Well, by this time in the movie, Kirsten Dunst has been expelled from the school and shouldn't be in that frame. We know this, and it is confirmed that she wasn't still at school by her appearance at the end of the film, when she arrives with Frosty in his car and says "We drove down as soon as we heard the news on the radio!" (01:27:00)