When Jimmy visits Mrs. McClure and pours himself a glass of Coke, the amount of Coke in his glass changes several times.
The smiley Jimmy draws on the window of Deirdre's car changes between the shot from the outside, and the inside.
In the scene where Jimmy's girlfriend has gone to his house to get her stuff, the collar on her sweater appears down when shown from the back. When the scene switches to her front, the collar is pulled up.