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.
Add timeMatty Blast
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.
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.
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.