![The Simpsons mistake picture](/images/screenshots/347000-347999/347612_sm.jpg)
Revealing mistake: When Grandpa is reading from the book trying to find out what is wrong with Maggie, the pages are blank. (00:09:30)
![The Simpsons mistake picture](/images/screenshots/334000-334999/334957_sm.jpg)
Revealing mistake: At the start when we see stuff falling off the roof, the animation for the swings in the background simply fade out and are incomplete. (00:02:05)
![The Simpsons mistake picture](/images/screenshots/185000-185999/185107_sm.jpg)
Revealing mistake: When Homer points at the donut guy, his right shirt cuff is colored yellow. (00:12:50)
Answer: Willy referred to an encounter he believed he had with actual aliens, while Wiggum thought he was referring to the arcade game.