The Wizard of Evergreen Terrace - S10-E2
Continuity mistake: During the very last scene Homer is sitting on the sofa next to Bart watching the news. But in the last shot he's sitting in a separate chair next to the sofa.
Thirty Minutes Over Tokyo - S10-E23
Continuity mistake: When Lisa gets the tickets on the "volcano", she is a few inches away from the end of the bridge. When it falls and Marge runs onto the bridge, she is now in the middle of it.
Continuity mistake: When Homer and Ned attempt to escape from their Vegas wives at the buffet. The Vegas Wives are directly in front of them, when Homer runs off he runs in an opposite direction, nowhere near them. When Homer runs out, the Vegas wives are right next to him.
Continuity mistake: While in the cafeteria, Principal Skinner asks Milhouse to lower his eyebrows. Behind him, there is a bulletin board that changes from brown to purple.
Continuity mistake: While Lisa is standing in front of the table with her friends in the cafeteria, we see that the trays appear during the first shot, then after the camera zooms in on Lisa's table, the trays disappear. Then during the third shot, Lisa calls Alex over to her table. Look at the table again: the trays have reappeared. (00:06:00)
Continuity mistake: When Lisa is getting the answers to her test, the coffee mug changes colors.
Wild Barts Can't Be Broken - S10-E11
Continuity mistake: Dr. Hibbert's clothes keep changing during the song near the end. He goes from having his white lab coat, a blue sweater, then a pink sweater.
Answer: Willy referred to an encounter he believed he had with actual aliens, while Wiggum thought he was referring to the arcade game.