When Hazel places a bomb beneath Jeff's car, Isabel and Josie are seen sitting in the front seats of the van, about to kiss. However, fifteen seconds later when the bomb goes off, Josie and Isabel are somehow in front of the van with the rest of the group.
During her meeting with Rhodes, the slices of bread on Josie's plate keep changing positions: in some shots they're lying flat, in others one is lying on top of the other. Additionally, Rhodes lighter moves on / off the table, depending on the shot.
During the opening scene, Josie's position in the bedroom changes almost every time the camera cuts between her and PJ.
When PJ and Josie are pitching their fight club to Principal Meyers, he goes from sitting on his desk to standing behind it between shots.
When PJ is reiterating Josie's plan to get the club back together to save the guys, the camera cuts to Josie and PJ's lips are mismatched with the audio.
The two actresses playing the high-school lead characters were 28 years old. They'd have to be very slow students to still be in high school at 28.