Continuity mistake: When we first see the sign outside the Quahog institute of performing arts, it has a cartoon take on the comedy and tragedy masks in the corners. In the left hand corner is a black mask with big ears and a smile and on the right is a white mask with a frown. Later on, the black mask has the frown and the white mask has the big ears and smile and the 3rd time you see the sign it has changed back again.
Continuity mistake: When Peter and Brian are escaping from the locals in their car, they go over a ridge. They freeze in midair and a voice says "those Griffin boys..." and the screen goes black. Then, in the next shot, the whole landscape is different. Even though the angle of the shot is different, that doesn't account for the disappearance of Chris and Sam or the colour-change of the sky. (00:14:40)
Continuity mistake: When Peter goes to see his ex-girlfriend, she says she never washed her hand and takes off her right glove to show a black hand. It is like this right up until Peter leaves. She then turns around and the hands have switched colours. (00:10:00)
Continuity mistake: Pay attention to the items behind the police auctioneer. In the first couple of shots we see a statue of a knight on a horse to the left of the auctioneer. When the camera cuts to Peter, and then cuts back, the statue is gone. The statue is then back in the next shot. (00:03:20)