Revealing mistake: The principal apprehends the two younger and bigger guys at once (and for some reason they don't gang up on him and kick his butt). The other guys in the Chevy decide to get back in and drive away. You can already see on the dirt the path they will follow, which is logical for the bit in reverse but not so much for the part when they turn left and go forward, which is not how the car could arrive to that point. And when later the car circles around, it moves also on a path that was not showing in the first shot. (00:11:50)
The Principal (1987)
1 revealing mistake
Directed by: Christopher Cain
Starring: James Belushi, Jim Belushi, Louis Gossett Jr., Rae Dawn Chong, Michael Wright
Continuity mistake: The protagonist just flushed down the drugs a girl was selling in a bathroom stall. She threatens him saying "Someone's gonna come lookin' for you." In the next shot, the shadow she and the other poofy-haired girl by the stall project on the door tripled in size. (00:33:30)
Victor Duncan: This school here is MY school. And I make the rules.
Rick Latimer: Not anymore.