Revealing mistake: When Mrs Arness and her dog, William Shakespeare, are at Peter's house, the dog walks over to Georgey. You can see the actor who plays Georgey had to hold dog treats in both of his hands to keep the dog near him in the scene. Confirmed in the audio commentary. (01:09:05)Super Grover
Revealing mistake: During the fight scene between Charlene and the girl, as Charlene hits the woman it is visible that she does not even touch her.