During the "Price is Right Cliff Hangers" cutaway gag, when the Griffins fall off the mountain, the traditional Price of Right "loss horns" play. This is an error, as Cliff Hangers is one of the very few games on the show that does NOT use the loss horns.
When Stewie and his date are walking down the boxing-arena steps, spectators are only three people deep from the aisle, then all empty seats. The animators got lazy with this scene.