Continuity: When the guy in suspenders sneaks a cassette tape of Harry's show into the boombox, at the place where the students are dancing, the recording of Harry busting Deever is a completely different performance. You can tell because the word "Why" (from "W-w-why is that, Mr. Deever?") is much lower in pitch.

Continuity: When the teachers play the confiscated tapes of Harry, it's Christian Slater's voice, not the disguised voice you hear on the students' radios.

Factual error: When Christian Slater is talking on the phone in one scene, it is clear it is a cordless phone. When he slams it down, however, it makes that "ding" sound like older phones that really have a bell in them.

Continuity: The entire 'typical American High School' wears the same clothes two days in a row, as a result of one day in the script which was divided into two days during the editing process.

Continuity: When Mazzilli is talking to the reporter in front of the school, he lights smoking firecrackers and throws them behind him. When we see him light the first one, it is at least three or four inches long when we see it in his hand, but much shorter an instant later when it hits the ground. This happens again with the next one too, but this time it's shorter when we first see it and slightly longer when it hits the ground.

Audio problem: Throughout the final sequence, when Harry and Nora are in the jeep and being chased by the police cars onto the field by the gym, many of the words Harry says are out of sync with his mouth.

Continuity: When Paige is shown brushing her hair in front of the mirror, there is no background shown in the mirror behind her; it's completely black. We see this a few times while she's sitting at the dressing table, but then when she gets up to gather her things and take them to the kitchen, we see the room reflected normally.

Continuity: In the scene where Christian Slater's character is talking to "Serious" (the kid who commits suicide), the letter he received from him is handwritten on lined paper. Earlier in the movie, there is a scene showing "serious" typing the letter on his computer.

Continuity: The FCC commissioner's limousine window goes up and down in between shots.

Factual error: Upon finding the cordless phone's base in the shed outside Mark's neighbor's house, the cop says, "There's the transmitter, which means the receiver could be in any house within 1,000 yards of here." I noticed no amplifier or anything to soup up the transmitter, and I know of no store-bought cordless phone with a range even remotely close to 1,000 yards.

Audio problem: Just about every time someone starts or stops a cassette tape, we can see that they're either faking it or pressing the wrong button. In one shot, the 'Pause' button is down both before and after the actor presses 'Play,' which would of course mean that the tape shouldn't play at all.