When Debbie first puts on the jumpsuit with the answers on it, it is unbuttoned. But when Pim puts on the sunglasses it's buttoned, and when she takes them off and they walk into class, the jumpsuit is unbuttoned again.
The sticker on Phil's forehead disappears after the camera switches to Crash.
During snacktime, when Crash spits the milk on Phil he doesn't have any milk on his face. But when the camera switches to Crash and then back to Phil, he has milk around his mouth.