Corrected entry: When Allison is sitting and biting her nails at the start, she is sitting facing away from the other students, but then when she notices Bender, Brian, etc., staring at her she is suddenly facing the front.
Corrected entry: In the scene where Andrew and Bender are about to get into it, Bender pulls out a switchblade, and stabs it into a nearby chair. The shot goes back to Andrew, and then goes back to Bender. In this shot, the switchblade is not stabbed into the chair.
Corrected entry: Bender has one white shoe on and one black shoe on in the gym, but the scene before he has 2 black shoes on.
Corrected entry: In the scene where the five are running through the halls trying to dodge the principal, they run past a window where it is full-on dark. Since the detention took place on a Saturday morning and afternoon, there is no way this could have actually happened.
Corrected entry: During the scene where Mr. Vernon asks for Andrew's help in putting the magazine rack in the doorway, he tells Andrew to be careful of the magazines when crossing back. Naturally Andrew slips and crushes some of the magazines. However, all Andrew had to do was use the adjacent door. Even if it was locked from Andrew's end, Mr. Vernon could have pushed it open for him on his end.
Corrected entry: At the beginning of the movie, Brian reads the beginning of his essay/letter to Vernon. It reads like this: Dear Mr. Vernon, we accept the fact that we had to sacrifice a whole Saturday in detention for whatever it was we did wrong. But we think you're crazy to make us write an essay telling you who we think we are. What do you care? You see us as you want to see us. In the simplest terms, in the most convenient definitions. But what we found out is that each one of us is a brain. The question, "What do you care?", disappears at the end of the movie when he reads it again, yet it's supposed to be the same essay he writes at the end of day.
Corrected entry: In the shot where the principal is talking to John in the closet, he takes off his suit coat. When he leaves the closet you see him pick something up (I think the coat) and he's wearing it when he's in the bathroom. When the shot goes back to John escaping, it shows John's jean jacket and a suit coat just like the one the principal has lying next to it. If he took his coat then why is another coat left there? I doubt he had two on.
Corrected entry: When John Bender (Judd Nelson) is in the gym shooting hoops and the teacher (Dick) comes in, Bender is wearing a white tennis shoe on his left foot and a black boot on his right foot. His white shoe comes off and is left in the gym so he's then only wearing one black boot on his right foot. The next time you see him and for the rest of the movie he is wearing black boots on both his feet. Where did the left black boot come from?
Corrected entry: A Shermer High School newspaper is shown with the headline "Clarke Sparks Grapplers." In the credits at the end of the film, Andrew's last name is spelled Clark.
Corrected entry: Following the scene where Bender shoves the "wad" down Brian's pants, we see him running past rows of lockers. As the camera aims to show the angle of the hallway, he heads towards a full-dark window. This isn't possible, since the detention was held during the daytime.
Corrected entry: After Claire gives Allison a makeover, Allison is wearing different clothes. Where did the clothes come from? Did they go shopping in the middle of detention?
Corrected entry: In the scene where Bender is in the gym shooting baskets, the teacher kicks the ball and Bender jumps out of one of his sneakers. You can see him slip the shoe off before he jumps out of it.
Corrected entry: Towards the end of the movie Allison reveals that she's attending the detention simply because she has nothing better to do. This was probably done to emphasize her being a loser with no life, but it's ludicrous in realistic terms. Vernon would have surely had a list of the students scheduled for detention, and would have immediately realized that one extra student was there who had no business being there. And as far as I know there is no High School that would allow a student to sit through a detention session just for the fun of it.
Corrected entry: The time on the clock in the hall is way different from when the troublemaker guy runs down the hall than the on the clock in the gym when we see him a second later shooting basketballs.