Audio problem: When Milhouse is saying he's getting swimmer's ear, his mouth is out of sync whilst saying it.
Audio problem: When the bus is flying off the bridge and Otto says "Which way should I turn?" look closely at him when we can see his face during the line. We can see his mouth is out of sync when he's saying it.
Audio problem: When Homer says God is his favourite fictional character, his mouth is saying something different to what we hear.
Audio problem: When Homer is placing objects on the dining room table to start his website, he is whistling but his mouth isn't moving.
Audio problem: When everyone runs towards the cooler on the next morning, they all cheer but their mouths don't move. (00:13:20)
Audio problem: When Bart takes Milhouse's inhaler to go after the cooler, Milhouse says "Hey, I need that to live". His mouth doesn't match with what he is saying. (00:12:15)
Audio problem: When Bart and Nelson are having a fruit race on the bus, the kids mouths don't move when they are yelling. This occurs in the wide shot. (00:05:40)
Answer: Willy referred to an encounter he believed he had with actual aliens, while Wiggum thought he was referring to the arcade game.