When Kylie and Quinn are talking while Kylie's hair is supposed to be stuck in the locker, when shown from the front, her head is in the middle of the locker. Both sides of the locker can be seen, and there is no hair stuck in it.
When Jamie disturbs the box with the birthday supplies it starts to fall, then there is a shot of Jamie falling. The box is never seen falling, but the next shot, Jamie is on the floor covered in balloons and other party supplies.