Tree House of Horror III: The Simpson's Halloween Special III - S4-E5
Corrected entry: At the beginning of the episode, Nelson punches Martin. Surely Marge would have noticed it, but she didn't.
Tree House of Horror III: The Simpson's Halloween Special III - S4-E5
Corrected entry: When Homer says that he is going to get Bart a birthday present, he runs to the car and drives away. Not only is it impossible for him to run out to the car, get inside, start the engine and drive away in the time he did, but he presumably used the back door (as we did not see him use The Front door). Why didn't he use The Front door? It would have been much quicker.
Correction: Matt Groening (the creator) has said that they decided to do an inside joke in the show of characters driving away too quickly, so when Homer does it, it is on purpose.
Tree House of Horror III: The Simpson's Halloween Special III - S4-E5
Corrected entry: In "Clown Without Pity", when Homer buys a Krusty doll for Bart, the guy at the shop doesn't give it to him inside a box. When Homer gives it to Bart, it is inside a box.
Correction: There may have been more than one item of this doll and the one he showed Homer was for display purposes. The fact that there was a phone number to call for problems with the doll makes it very possible this wasn't just a one off doll. Even if there hadn't been more than one, he may have packaged it up before Homer left the store.
Tree House of Horror III: The Simpson's Halloween Special III - S4-E5
Corrected entry: In "Clown Without Pity", where the Krusty doll acts as Homer's servant, Homer says at one point "Yeah, dogs like to bury old junk", in which the Krusty doll says "Yeah, you stupid idiot.." The 'you stupid idiot' part is said with his mouth closed. (00:07:15)
Correction: Not really a mistake. She just didn't notice it.