Homer Badman - S6-E9
Continuity mistake: After Marge's left pocket rips in the candy convention, she goes to start picking up the candy when we see that the right pocket has ripped all of a sudden. When Homer and Marge start running away the pockets are no longer ripped and full of candy again.
Continuity mistake: When the burglar points the gun at Apu and says "Hand over all your money in a paper bag" Apu immediately replies "Yes, yes, I will". But when Bart sees this incident on TV later, the time between the burglar demanding the money and Apu replying "Yes, yes" is much longer.
Diatribe of a Mad Housewife - S15-E10
Continuity mistake: After the clown balloon that rips at the car dealership there is a bit of material left over and there is also a cord attached to the wooden platform where the balloon was. After a reaction shot, it cuts back and the material and the cord have both disappeared.
Lisa's Date with Density - S8-E7
Continuity mistake: As Homer is walking out of the Kwik-E-Mart, after Apu refuses him the donut, he has nothing in his hands. In the next shot from outside the store we see him carrying a small paper bag.
Dude, Where's My Ranch? - S14-E18
Continuity mistake: Carla's "Carla" ring is only on her finger in the closeup.
$pringfield (or How I Learned to Stop Worrying and Love Legalized Gambling) - S5-E10
Continuity mistake: When Homer makes the food with the mix of Tom Collins mix, cloves and a pie crust you can see the labels on the Tom Collins mix and the cloves change between mixing the ingredients and after tasting them. Also the top on the Cloves bottle keeps changing through the scene. When Homer takes the bottle out of the fridge you can see a red top on it. When he sits down the top has disappeared and starts pouring the cloves. When the shot changes the red top is back and it disappears after that. (00:15:20)
Continuity mistake: When Lisa decides to take Miss Hoover's Teacher's Edition, we see "Teacher's Edition" on the spine of the book. But when Lisa puts it in her bag the spine of the book is completely blank.
Continuity mistake: In this episode Hans Moleman's skin colour is yellow. However in "Duffless " his skin colour is brown and in other episodes it is a dark yellow-green colour.
Home Away From Homer - S16-E20
Continuity mistake: Ned's front door before he and his family leaves opens on the left side (when looking at it from outside), but after the "Coach" has moved in, it opens on the opposite side.
Continuity mistake: When Nelson asks Bart what song he is playing as they wait for the bus, Nelson's vest is orange and his shirt is bluish. However, when the bus arrives and Nelson goes to get on the bus his vest is now bluish and his shirt orange. (00:10:10)
Continuity mistake: In the scene where Homer is going down the escalator, in the Costington's Centre, after he gets on two men follow him, then a woman, yet when the shot changes, it's a man then a woman then the other man. (00:00:45)
Continuity mistake: Near the start when Marge is putting jam on bread, she spreads it on the last piece but as she puts it on the plate it changes to a blob in the middle.
Continuity mistake: When Homer is driving to Truckasaurus there is a wide shot of the road with two cars on it, but in the next side shot of the road, the road has loads more cars on it. (00:06:30)
Continuity mistake: When Marge is cleaning the dishes on the morning after Bart reveals Lisa as a nerd, Marge is seen in close-up with a white necklace. In next shot of Bart and Lisa, as well as the rest of the scene, Marge has a red necklace.
Sideshow Bob's Last Gleaming - S7-E9
Continuity mistake: When Bart and Lisa first enter the Duff Blimp, Bart doesn't have his back-pack on. However, he is suddenly wearing it after the bomb has gone off.
Continuity mistake: When we see the wide shot of all the houses going along the road, you can see that Moe's door is facing away from the Simpson's house. But in the next shot, Homer jumps in through Moe's door, it's like the tavern did a 180 degree turn.
Secrets of a Successful Marriage - S5-E22
Continuity mistake: When Homer comes into the kitchen he is holding a pipe in his left hand. But in the next shot you see him holding up the ruined jacket with his left hand, then in the next shot his hand is back in his pocket.
Much Apu About Nothing - S7-E23
Continuity mistake: Homer comes to the Kwik-E-Mart with the new 'American Apu' and sees him reading a magazine. When Apu walks over to Homer, his magazine disappears.
Answer: Willy referred to an encounter he believed he had with actual aliens, while Wiggum thought he was referring to the arcade game.