Continuity mistake: When Bart is talking to Jessica after she stole the collection plate money, she is far away from Bart. But when Bart says "but you're not very nice", she is right next to him.
Continuity mistake: After Homer's emotional outburst about the lack of bananas, when it cuts to the exterior shot of the Lovejoy house the doorknob is on the right side of The Front door, but when Reverend Lovejoy kicks Bart out of his house, the doorknob is on the opposite side. Later, when Jessica twirls the baton, the doorknob is on the right side again. (00:08:00)
Revealing mistake: When all the students are leaving Springfield Elementary after the fire alarm is pulled, the same students keep passing over and over again.
Answer: Willy referred to an encounter he believed he had with actual aliens, while Wiggum thought he was referring to the arcade game.