Audio problem: After Barney falls over in his chair, you can hear him say, "Hmm, a pretzel." His mouth doesn't move. (00:21:15)
Audio problem: When Otto says that he was on his way to Mexico, his mouth doesn't move in the interior shot of the bus. (00:04:20)
Answer: Willy referred to an encounter he believed he had with actual aliens, while Wiggum thought he was referring to the arcade game.