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.
Continuity mistake: After Conway Twitty finishes his song, the scene cuts back to Perter and his family at the kitchen table. Take notice that Lois is sitting next to the back door, and Brian is sitting next to the kitchen sink and window. Keep an eye on that kitchen sink, window and door, because it will be replaced by a yellow wall with the telephone now being closer to Lois. Later as Lois, Brian and Peter are discussing OJ Simpson, the sink, widow and door return.
Continuity mistake: In 'Wasted Talent', near the end of the Chumba-Wumba song about Joe being in the wheelchair, the Chumba-Wumbas wheel Joe till he is about 15 yards away from the gate. Then as the shot cuts, Joe and the Chumba-Wumbas are standing right next to the gate. How did this happen? Nobody moved him.
Continuity mistake: When Peter, Anne Frank, and a group of people (presumably Anne Frank's family) are hiding from the Nazis, Anne Frank and her family look over to discover Peter munching crisps. In the next shot, Anne Frank's family look somewhat different, in fact they are a different group of people entirely.