Homer's Triple Bypass - S4-E11
Continuity mistake: When we first see Krusty start talking to Homer, from the rear shot you can see Krusty is missing his pale colour on his face. However, in every other shot, his pale complexion is there. (00:15:10)

Homer's Triple Bypass - S4-E11
Continuity mistake: When Krusty bursts into the room, the shot ends with him having his arms and legs bent. In the next shot, he's straight as a ruler. (00:15:10)
Homer's Triple Bypass - S4-E11
Continuity mistake: When Barney and Moe visit Homer, the vase of flowers disappears and then suddenly reappears at the end of the scene. (00:16:10)

Homer's Triple Bypass - S4-E11
Continuity mistake: When we see Bart pacing when Homer is having his operation, he is on the rug in the overhead shot and by the rug in the regular shot. (00:18:50)

Homer's Triple Bypass - S4-E11
Continuity mistake: When Homer is having his operation, and Dr. Nick says, "I know I'm supposed to cut something, but what and where?" his moustache disappears three times. (00:19:50)

Homer's Triple Bypass - S4-E11
Continuity mistake: When, Lisa bangs on the window of the operating theatre, there is a person sitting behind her who is asleep. However, when she shouts to Dr Nick, the people behind her are completely different. Then she sits down again, and the sleeping person is behind her. (00:20:00)
Homer's Triple Bypass - S4-E11
Audio problem: When Lisa is watching Homer have the operation, she shouts "below" but her mouth is closed. (00:20:05)

Homer's Triple Bypass - S4-E11
Continuity mistake: When Nick gives the news about Homer's recovery, the books on the table next to Marge change between shots. (00:20:30)
Homer's Triple Bypass - S4-E11
Factual error: I get it, it's a comedy. But after open heart surgery, you are sedated for 1-2 days and on a ventilator. So, Homer even being awake after open heart surgery is completely false. Also, as someone who has had open heart surgery, you can barely move your chest because your sternum is fractured.
Marge vs. the Monorail - S4-E12
Revealing mistake: When Homer is driving along and singing, he passes three houses in the background. Those exact same houses reappear three times in the same shot even though he never turned around. (00:01:15)
Marge vs. the Monorail - S4-E12
Continuity mistake: At the beginning of the episode, Homer slides down a big pipe and smashes through one of the windows on the right side of the car. But when Homer crashes into the chestnut tree, it is fully repaired. (00:01:25)
Marge vs. the Monorail - S4-E12
Other mistake: When Homer crashes his car, he just disappears when it hits the tree. (00:01:50)
Marge vs. the Monorail - S4-E12
Continuity mistake: When Grandpa Simpson stands up in The Town hall, the position and amount of paintings on the wall change several times between shots. (00:06:10)
Marge vs. the Monorail - S4-E12
Continuity mistake: When Quimby states to Lyle that Springfield is twice as smart as Shelbyville, Quimby lowers his gavel at the end of the line. In a sudden close-up of Quimby, his gavel is raised again. (00:07:05)
Marge vs. the Monorail - S4-E12
Other mistake: Lanley's desk in his trailer suddenly gets brighter even though none of the lights in the trailer were turned on. (00:12:50)

Marge vs. the Monorail - S4-E12
Continuity mistake: Cobb's hair in North Haverbrook changes length between shots. (00:14:10)
Marge vs. the Monorail - S4-E12
Revealing mistake: When the passengers board the Monorail, Homer begins pushing two buttons. The second button he pushes is just the counter. There is no button there. (00:15:40)

Marge vs. the Monorail - S4-E12
Continuity mistake: When the sticker reveals the 1964 world fair sticker on the monorail, the world fair sticker is blue. Shot changes to a high angle shot and now the sticker is white. (00:16:40)
Marge vs. the Monorail - S4-E12
Continuity mistake: Just after the Monorail has been seized by the "anchor" getting caught on the donut sign, the long stripe at the top of the side of the Monorail changes from being red to purple.
Marge vs. the Monorail - S4-E12
Audio problem: When goes to the Monorail Café, the woman there says to Marge "Go away" but her mouth doesn't move.





