Other mistake: The amount of gunk that come from Bart's model at the start is not proportionate to the size of the model. In other words, there couldn't be enough gunk to cover the entire inside of the bus.
Other mistake: When Homer returns home, Marge says his car is blocking the traffic. But there is some space on the road where his car isn't. The traffic could easily have driven through the empty space. (00:02:30)
Other mistake: When Marge takes Homer back inside, his car is seen blocking the traffic. But at least one side of the traffic is driving on the wrong side of the road. The drivers behind Homer's car are on the right side of the road. And the drivers behind Homer's car from the opposite direction are driving on the left side but facing the drivers behind Homer's car on the other side. Either way, one half of the traffic are driving on the wrong side of the road. (00:02:35)
Simpsons Bible Stories - S10-E18
Other mistake: Rev. Lovejoy is reading Genesis, the first book of the bible, but he is a good way into the book. Surely it would be at The Front?
Other mistake: When the Simpsons' drives the electaurus off the edge of the harbour, it is shown that The Front of the car goes downwards. When it cuts to the interior view with the Simpsons' screaming, the view from the back window is tilting down, suggesting the rear is going down and The Front coming up. But in the next shot the car is seen in the water with The Front down.
Guess Who's Coming to Criticize Dinner - S11-E3
Other mistake: In the German version, the Italian cook peeved by Homer's comment on lasagna swings the cleaver at him using an Italian word ("Porcodio") which is a rather strong blasphemy, way stronger than any other expression used in original or in other localizations worldwide.
Tree House of Horror X - S11-E4
Other mistake: In "Desperately Xeeking Xena", at one point she approaches the Collector, who is about to get a light saber. We can see the back of the pouch that Xena is in, but the tape on the other side isn't visible, even though it is a transparent pouch.
Other mistake: In the scene set in the future after Lisa, as the US President, held a conference with some journalists, just before the scene changes they show a black journalist with eyes not drawn among the crowd.
It's a Mad, Mad, Mad, Mad Marge - S11-E21
Other mistake: When the kids are holding the video cameras, there is no strap to keep their hands on the camera, so it looks like their hands are glued to the side.
Other mistake: When Lisa says Bart's got a girlfriend, Bart says "no, I don't, that's the problem", his neck becomes longer and starts to wobble, a problem with the animation.
The Bart Wants What It Wants - S13-E11
Other mistake: Ned Flanders wins the $100 bill, but on the side it says $50.
Little Girl in the Big Ten - S13-E20
Other mistake: Sherri and Terri are seen participating in the second grade gymnastics (as referred by the gym teacher), even though they're in the fourth grade.
The Dad Who Knew Too Little - S14-E8
Other mistake: When Bart flashes Lisa's laser at Principle Skinner's bottom, Chief Wiggum can still see it even when his car is in the way.
Scuse Me While I Miss the Sky - S14-E16
Other mistake: Bart and Lisa overload the nuclear power plant to create a city-wide blackout so everyone can see the meteor shower. All the lights in Springfield blow out. Yet when we see the Simpsons sitting on their lawn watching the shower, every single window in their house is yellow, as if every room has their lights on. It is the only house shown with power.
Other mistake: When the Amish are building the tree house, the top of the tree is missing. It's just sky. In the next shot the top of the tree is back.
My Mother the Carjacker - S15-E2
Other mistake: In the scene where the prisoners are singing along with Mona, two inmates have the same Identity number.
I, (Annoyed Grunt)-bot - S15-E9
Other mistake: When the bullies are riding around Bart and Milhouse there are problems with their water bottles. In some frames they vanish, in some others the bullies' far legs are drawn in front of the bottle. (00:01:40)
Other mistake: When Moe is rolling his eyes after saying it was the first time he poured beer into the water supply, Herman's face is drawn incorrectly.
Other mistake: At the end when Bart and Homer are singing "twinkle twinkle little star" Bart's tongue is green.
Other mistake: When Homer is being interviewed while feeding baby Lisa, there's a picture of 8 year old Lisa in the background.
Answer: Willy referred to an encounter he believed he had with actual aliens, while Wiggum thought he was referring to the arcade game.