Continuity mistake: When Lisa arrives home after her parents gave the boy a party, she parks her bicycle near the path. When Lisa sees the boy with make-up on his face in the next shot, the bicycle is on the grass.
Continuity mistake: When Lisa and Tumi are listening to the radio in Lisa's bedroom, the door behind them changes position between shots.
Continuity mistake: When Lisa and Tumi have finished their square dancing, there is nothing to the left of the basketball stand, but when Lisa and Tumi are talking in the next shot, three balls have appeared.
Continuity mistake: When Homer reveals the murderer in the story, he is holding a card in his right hand. When Booth tells Homer he has given away the game, the card has disappeared.
Continuity mistake: When Marge and Maggie check out their groceries at the supermarket, the cashier says that she requires a price check on Gramma Shortcut's Store Bought Bundt Cake. The position of the cake on the scanner changes between shots.
Continuity mistake: In a full view of the checkout, when the cashier requires a price check on Gramma's Shortcut Store Bought Bundt Cake, you can see beside Marge there is a stand and there is a man with a beard and glasses behind it. When we see Marge in the next shot, the man is now standing behind her, and there is also a couple who weren't there previously.
Continuity mistake: When Marge puts down a dollar note on the scanner and takes the cake before leaving the supermarket with Maggie, the position of the dollar note on the scanner changes between shots.
Continuity mistake: When the man is talking to the cashier in the supermarket after Marge and Maggie left, there is a dollar bill on the scanner. When the cashier tells him to "shut up", the dollar bill has gone.
Continuity mistake: In a full view of Ear Poison on the stage at the block party, there are two guitarists next to the drummer, who were not next to him in the previous shot.
Continuity mistake: In the cafeteria scene, the shots from Lisa's perspective show glass protectors with signs where the food is. However, when the shot switches to Lunch lady Doris' perspective, the protectors are gone.
Treehouse of Horror XVIII - S19-E5
Continuity mistake: When Marge shoots Chief Wiggum, the arrow goes through his tie. When they roll on top of him, the arrow isn't through the tie anymore.
Continuity mistake: The door to Mrs. Krabappel's classroom has a window, but when Bart fakes being sick then walks out of the class (we see the desks as the door closes), the door's window has vanished, and the doorknob has switched sides as well. Additionally, earlier, when Bart deliberately falls off his chair in class, note that one of the bars on the back of his chair has gone missing. (00:07:35)
Please Homer, Don't Hammer 'Em - S18-E3
Continuity mistake: As the workmen begin to leave site after hearing that Homer is unable to pay them, a couple of tools are dropped on the ground; however, in the following shot, facing back towards the cabinet where Homer is hiding, the tools have disappeared.
Continuity mistake: After Mrs. Krabappel asks Bart to name the pirate in Treasure Island, when it cuts to a closeup of Bart we see the set of blue books have vanished from Mrs. Krabappel's desk, and a Krusty mug has suddenly appeared there. (00:03:00)
