Other mistake: When Joe Clark first comes to Eastside High as principal, he takes it upon himself to confront the staff. At one point, as he begins to turn his back, watch his lips. His mouth does not match the words being spoken.
Continuity mistake: When Joe Clark is having his talk with Sams on the edge of the roof of the school, Sams is on the right and Clark is on the left (when viewed from the ground). When they're done talking, Sams turns to his left and walks away - turning to his left would have made him fall off the roof after just a few steps.
Factual error: In the scene where Joe Clark and the Vice Principal go to the project buildings to see the young girl's mother, they walk down a short ramp to an apartment. Those project buildings are in Paterson,N.J. (where the story takes place), but walking down that ramp takes you to the boiler room, not an apartment. None of those buildings have apartments like that.
Factual error: Just after the opening credits, Thomas Sams is stuffed into a locker by two other boys, but a big kid like Sams would never fit into a real high school locker.
Audio problem: After throwing what looks like a toilet through the window, the two guys give each other a high-five. Their hands almost completely miss each other, yet we still hear a loud clap.
Continuity mistake: When the superintendent and the lawyer come to tell Clark about the Mayor and Fire Chief's plan to catch him chaining the doors (about 1:15:00), Clark is wearing a white tie with red stripes. At first, when Clark is walking down the hall with them, his tie is about 1 1/2 inches above his belt buckle (just above the bottom button of his shirt). Then, when he walks into his outer office with the Hispanic students, his tie suddenly creeps down about 3/4 of an inch (it is now slightly BELOW the bottom button of his shirt, and less than an inch above his belt buckle). At 1:16:45, when he walks into his inner office to meet with his teachers and security guards, his tie stays in roughly the same place. Later that day, when he is confronted by the female vice-principal in the hallway (about 1:18:20), he is wearing the same tie, but it is now hanging just BELOW his belt buckle. Clark may have adjusted his tie between his meeting with the teachers and guards in his office, and encountering the vice-principal in the hall, but he could not have done so instantaneously when he walked into his outer office from the hallway. (01:15:00 - 01:18:20)
Continuity mistake: In the first assembly, Sams and his friend are on the stage behind the guys beatboxing. The next cut is the teachers asking Sams and his friend to go up to the stage.
Audio problem: In the scene when Joe Clark takes Thomas Sams and the other boys into the music room, he slams Thomas Sams into the piano and you hear what sounds to be like keys being pressed down. However, he hit the side of the piano, so the only way sound could have come out is if his hands were over the keys. The way he hit the piano, it was not possible to produce any type of sound.
Factual error: The dates used in the movie were inaccurate. For starters, in the auditorium scene, Joe Clark said that the minimum basic skills test would take place on April 17. April 17, 1988 was on a Sunday. Also, when they did the countdown, 99 days before that date would have been Saturday January 9 (they couldn't have updated the sign). And in the scene when Ms Levias is yelling at Joe Clark, she said 'for the past 7 months' - it was only April, but he came in October (6 months earlier).
Other mistake: When Mrs. Barrett spoke out at the parent's meeting after the expulsion of the bad kids, she shouted out 'he insulted the black football coach'. Joe Clark insulted him at a staff meeting, and she wasn't there. How could she have possibly known about it?
Suggested correction: Because Clark demoted a black coach and replaced him with a white coach. Some black people would consider that an insult.
Character mistake: When Mrs. Barrett is on the school board stating her case, she said that the test scores on the practice exam were 35% below passing. Earlier in the movie, when Joe Clark opened the letter, the Eastside passing score was 33%, which was 42% below the required passing score of 75%. Since she was trying to get him removed, it would have been to her advantage to say 42% instead of 35% - 35% would have made it 68%, which would have still not been enough to pass.