Continuity mistake: Linderman supposedly pulls his bike out of the water before his fight with Mike. Neither he or his bike is the least bit wet.
Continuity mistake: When Clifford picks up his schedule on the first day, the lady tells Cliff where room 327 is. He then confronts a teacher in a brown polka dot shirt in the hall and asks her where 235 is. He then proceeds to enter home room 327.
Revealing mistake: Linderman refuses Clifford's offer to be his personal bodyguard from Moody's gang, and leaves. As Clifford walks by the students practicing their violins, playing Mozart, their bow movements do not match the music.
Continuity mistake: When Clifford is running down the hallway from Moody and his gang, Moody closes in on him by almost 40 feet. In the following shot, outside the auditorium, Clifford is a greater distance from the gang, sighing relief at the apparent getaway. Unless he suddenly picked up speed rounding some hallway corner, the time distance is impossible.