When Peter is telling the story of Nate Griffin he says that Nate and his family escape on a cart being pulled by a white horse. The horse starts out white in color but for a brief moment when the shot changes the horse is brown. When it flicks back again, the horse returns to white.
When the Griffins are arguing about The Godfather (1972), Chris mentions that Robert De Niro is in the film. He is not; he plays young Vito Corleone in The Godfather Part II (1974).