The index card in the open drawer.
The stool that Brian knocks over before he cries
Andrew's last name is spelled without an "E" in the credits.
When Bender runs down the hall to the gym, you can tell it is night outside through the window at the end of the hall.
The clock in the library changes during the same scenes throughout the movie.
Andrew screams and shatters a window upstairs. This window supposedly has wire framing in it, but ceases to remain after the shattering of the window.
The position of the chair after Bender takes the screw from the door.
During the discussion the Club has while sitting on the floor, Claire's hairstyle changes back and forth from one shot to the next.
Brian's watch switches position while explaining why he’s in detention.
While Bender is crawling through the ceiling, you can see the chain for his wallet while he's crawling in both directions.
Listen carefully you can hear someone feeding ally sheedy her line.(turn your sound up though)