Continuity mistake: When you see a shot of the church from outside in the scene where the bee sharps sing there, look closely at the sign. You can see that it says 'Also: The Bee Sharps', only they don't name themselves that until later on in that episode.
Continuity mistake: When Homer gets thrown out of the house by Marge and Otto walks up to him, you can see that it is Smithers and Carl standing behind Homer. Yet in the next shot when you see Homers face, you can see it is now Principal Skinner and Carl standing there.
Continuity mistake: When the person delivers the animation cell, his skin changes from white, to brown and then back to white. When Bart looks through the letterbox to see who was there, his skin is white. When he gives the box to Bart, it is brown. When he hits Bart in the face and says "that's for keeping me waiting", it is white again.
Continuity mistake: The man conducting the tour of the box factory tells the children that they will not be able to see a finished box, as the boxes are assembled in a separate location. However, moments earlier we saw a flat box going through a machine, and coming out finished.
Continuity mistake: When Marge comes home after the bogeyman incident, Homer trips over a footrest. You can see Bart sitting there however his pyjama's are a dark green color when before they were a bright green color.
Continuity mistake: At the end just before the Simpsons say "Happy Halloween everybody" they are about to bite Lisa (and make her a vampire). Maggie has no dummy (or in America, pacifier) in her mouth, but it suddenly appears when she closes her mouth.
Continuity mistake: As Marge arrives home and sees the bullet holes in the door, the shot changes to a POV shot from behind the door and you can see there are some changes in the holes. The first change is there are three bullet holes on the right hand side which are all the same distance from each other, when she enters the middle hole has moved closer to the bottom one. The other change is the large hole in the middle of the door. On the bottom right hand side its shape goes from being a little irregular to a more round shape.
Continuity mistake: Near the beginning of the episode, Bart is thinking what it would be like to get out of school, you can see his desk quite well and there is nothing on it. But when Bart has finished thinking, a piece of paper has just appeared on his desk.
Continuity mistake: At the end of the episode in church when the group of parishioners moves forward to forgive Ned there is a woman amongst the group who has light green hair. However, when there is a wide angle shot of the group again she is nowhere to be seen.
Add timeTobin OReilly
Continuity mistake: When Chief Wiggum and Homer think that the convertible Ruth and Marge are in is a ghost car, they want to hold each other. In this shot, you can see 1 small star out of the backseat of the police car. But in the next shot, from the perspective of the backseat, there is a canyon top where the star would be.
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.
Continuity mistake: In the air duct, the dog comes up behind Willie in a straight line and licks his feet, we saw what the duct looked like when Willie turned around. However, when the children start throwing stuff at the duct, from the outside there is a sharp bend right behind where Willie and the dog are that wasn't there in the internal shots.
Add timeDavid Mercier
Continuity mistake: When Homer sees Marge and Moe near the end, the coffee table changes size between shots. It's large when Moe sits on the couch.It's smaller when there's a shot of Homer and long again when the high shot shows Homer walking out (when his rags are stuck on it)
Continuity mistake: As Bart is on the phone trying to book his new act, you can see there is a split down his white shirt. When the shot changes and he tells Lisa to be quiet you can see that split has disappeared.
Continuity mistake: When Lisa and Marge go on the tour, when the film has finished the woman turns it off with a remote controller and puts it behind her back. In the next shot from behind her it isn't in her hands and there is no sign of a pocket or any indication she put it anywhere else.
Add timeDavid Mercier
Continuity mistake: At the "Do What You Feel" Festival, Homer shows up in his house robe, bear feet styled slippers, unshaven, and unbrushed hair. When he takes the float to save Bart, he's in his regular clothing of blue pants, white shirt, shoes, and clean shaven.
Add timeMovie Nut
Continuity mistake: When the Simpsons are leaving the house to go to the mall. The aerial shot shows that they are leaving in Marge's red station wagon, but the very next shot of them in the car shows that they are in Homer's pink sedan. The shot of the station wagon leaving is probably a re-used shot from a previous episode.
Continuity mistake: Immediately after being chained to a tree, Stampy crushes several objects (a lawnmower, a bike, a doghouse, and a trash can). In the very next shot, which comes after a commercial break, all of these objects are in fine shape. Then the shot changes again and we see them destroyed once again.