Continuity mistake: When Homer is at the retirement party, there is a far shot of him (when Smithers talks to Mr. Burns) and he isn't wearing his jacket. In every other shot Homer is wearing his jacket. (00:05:20)
Audio problem: Ms. Krabappel is telling Bart about the laundry list of sicknesses he had to get out of the test. You can see her mouth doesn't match up when she mentions "...and that unfortunate case of rabies." The studio actually changed what Ms. Krabappel originally said which was "and that unfortunate case of "Tourette's Syndrome." [Some reports say that the original line of Tourette's Syndrome was left in syndications in certain areas. On the DVD version the rabies line has been used]. (00:16:00)
Continuity mistake: When Homer says, "You can't take our donuts," his hat is red. But in the next shot and in every other shot of Homer, his hat is blue. This is pointed out on the audio commentary on the Season 4 DVD. (00:12:35)
Continuity mistake: When the family is at dinner, there is a top down view which zooms in on them from above. In this shot there is no newspaper on the chest (to Homer's left). In the next shot of Homer a newspaper has appeared. (00:07:50)
Other mistake: When Lisa checks Marge's resume, she reads it and turns it over. But there is no text on the back as there should be. (00:06:30)
Continuity mistake: Willie rips off his entire shirt before he fights the wolf, but in the next scene, when he is wrestling the wolf, he is wearing a torn-up shirt. (00:18:40)
Continuity mistake: After Bart is attacked by the wolf and goes back into class, the banner above the chalkboard that has the alphabet on it is blue. Every time we see the banner after that it is yellow. (00:18:40)
Continuity mistake: When Mr Burns draws the moustache and horns on the T.V. screen of Marge, they just disappear in the next shot when he starts to draw the bees. (00:19:30)
Continuity mistake: When Bart comes back into the classroom after the wolf attack, Ms Krabappel is writing on the black board and there is quite a bit of writing up there. After we see Bart the shot goes back to Ms Krabappel and all the writing has gone. (00:18:45)
Continuity mistake: Mr. Burns gives Marge a present when she starts her new job. The present is light purple with a red ribbon around it. Seconds later though, the present turns to orange with a red ribbon around it. (00:11:45)
Continuity mistake: When the wolf runs out of Krusty's studio, the woman who described it changes from having two gloves on to one glove on. (00:16:40)
Continuity mistake: When Homer and Marge come home from the dinner, Marge is wearing a fancy dress. But when Bart falls out of the house right after Homer walks in, she has her typical green dress on. (00:06:15)
Character mistake: Lisa states that Pierre and Marie Curie both died of radiation poisoning. This is incorrect, as only Marie died of radiation poisoning while her husband Pierre was killed by a horse and cart. (00:08:30)
Continuity mistake: Lionel Hutz runs out of Burns' office leaving both doors open. When Marge says about going, they are closed. (00:20:20)
Continuity mistake: When Homer is talking about Marge getting a job at the dinner table he has a spoon in his hand. Once Marge has finished scowling he doesn't, and there isn't one on the plate either. (00:08:05)
Revealing mistake: When Grandpa is reading from the book trying to find out what is wrong with Maggie, the pages are blank. (00:09:30)
Continuity mistake: We see the items fall off the roof but a Christmas ornament is not among them. However one lands on the ground with everything else. (00:02:05)
Continuity mistake: When stuff is falling off the roof, in the long shot there is nothing on the roof but in the close up there is. (00:02:05)
Continuity mistake: When Bart is out in the hallway being attacked by the wolf, he is missing his right shoe. When he goes into class he is missing his left shoe. (00:18:40)
Continuity mistake: When we see Krusty with a bird on his head, the claws' position on Krusty's head change. Note his left eye. (00:16:20)
