Continuity mistake: As Chief Wiggum is being interviewed about the fugitive, his arm is shown to be in a cast due to the police van crashing at the Krusty Burger Drive-Thru earlier on. Yet when they get to the hospital, his arm is completely fine. (00:17:30 - 00:19:00)Casual Person
Continuity mistake: In Lisa's music class, there is a wide shot of the entire class. Üter sits next to Milhouse Van Houten in this shot. However, in the next shot, it's Ralph Wiggum. In a following shot of the entire class, it's Üter again. They both replace each other in the same seat.
Continuity mistake: When Homer is freaking out and starting to hallucinate after eating a few peppers, Jasper is behind a tent stall when Homer is running away from Ned Flanders, but just seconds later when Homer falls to the floor, Jasper is in front of Homer.
Continuity mistake: The seating arrangements during the Cheech and Chong show keep changing between shots. Smithers is first seen sitting between Patty and Luigi, then he is between Louie and Legs, and then he is between Patty and Luigi again, then finally, he is sitting next to Mr Burns. And Miss Hoover is at first two rows in front of the Simpsons, then she is a row behind them when Homer is going to the stage.
Continuity mistake: This is a mistake for the introduction from seasons 2-20 (1991-2009). When Homer screams, he turns round. You see this in a wide shot. There are no boxes to the right of the door in the garage. However, two just appear out of thin air when he runs through the garage. (00:01:50)