Continuity mistake: When Homer stands outside the Bouvier house to pick up Marge, the home's front door has three diagonal windows from upper left to lower right. However, when Marge gets home later after the prom, the three windows are diagonal the opposite way from upper right to lower left. (00:16:10 - 00:21:00)
Revealing mistake: While Homer is waiting for Marge to come downstairs, both Patty and Selma are wearing turtlenecks. When Homer thanks Mr. Bouvier, in the next wide shot as the twins nod their heads, both of their turtlenecks are not colored in properly at their torsos, so the background is visible through their bodies. (00:16:30)
Continuity mistake: When Marge comes downstairs she's shocked to see Homer in her house, and when the doorbell rings we see Mrs. Bouvier wearing an orange belt with a red buckle, but then the colors switch to an orange buckle and the belt center is red. (00:16:45)
Homer vs. Lisa and the 8th Commandment - S2-E13
Continuity mistake: When all the kids run out of the back door, Homer drops a blue box. In the next shot it is a yellow box with red lines on the edges.
Homer vs. Lisa and the 8th Commandment - S2-E13
Continuity mistake: When Homer and Marge are discussing about unhooking cable, the time on the clock on Homer's bedside table changes between shots.
Homer vs. Lisa and the 8th Commandment - S2-E13
Continuity mistake: When all the kids are watching TV, we see Wendell, Martin and Milhouse. Absurdly they appear to be right below the ceiling in this shot - when in every other shot they are sitting on the sofa or standing.
Homer vs. Lisa and the 8th Commandment - S2-E13
Continuity mistake: In every other episode, the bar at Moe's Tavern is a regular L-shape. In this episode, it has somehow gained two additional angles on the long side, making it a Z-shape (plus the angle to the short end, which is not shown).
Homer vs. Lisa and the 8th Commandment - S2-E13
Continuity mistake: At Sunday school, Milhouse's jumper changes from black to red between shots.
Homer vs. Lisa and the 8th Commandment - S2-E13
Revealing mistake: When Homer is imagining being locked in the jail cell and he turns around to find he is in his own home, he turns to look at his family. There is a close up shot of his terrified face, and the people in the background watching the game (I think it might be Lenny and Carl) have no eyes. The rest of their face is fine, but their eyes are missing.
Homer vs. Lisa and the 8th Commandment - S2-E13
Continuity mistake: When Bart and Lisa are at Sunday school, the teacher writes "HELL" on the board, which changes from being red to black between shots.
Homer vs. Lisa and the 8th Commandment - S2-E13
Continuity mistake: When Homer is sitting watching cable, the rest of the family comes home and one of them is carrying a plant in a pot, which is put down next to the couch. While they watch and watch cable, it grows very tall and then withers down. When Homer goes behind the TV and starts kissing the wires, the plant has moved to next to the doorway and is suddenly fully grown again.
Homer vs. Lisa and the 8th Commandment - S2-E13
Continuity mistake: When the family are outside, in the shot just after Homer says "At the worst possible time" you can see the living room - everybody has disappeared in that shot.
Homer vs. Lisa and the 8th Commandment - S2-E13
Continuity mistake: When the door is answered to Mr Burns and Mr Smithers, Barney is seen answering, who has orange sleeves. However when the door is opened, you can just make out a white sleeve, which could be none other than Homer's.
Revealing mistake: In the shot of Skinner admiring his tater tots, he is interrupted and lifts up his tray. As he inspects he tilts his tray to at least a 90 degree angle but everything, including the milk, stays in exactly the same spots.
Continuity mistake: Patty and Skinner go to see 'Space Mutants IV: The Land Down Under'. In a season one episode, 'The Telltale Head', a sign on the Springfield Aztec movie theater reads 'Space Mutants IV: The Trilogy Continues'.
Audio problem: When Patty says "Marry me Patty?" while reading Skinner's message, her mouth doesn't move.
Oh, Brother, Where Are Thou? - S2-E15
Continuity mistake: When Herb, Bart and Lisa are watching Itchy and Scratchy, Herb goes from wearing a t-shirt and shorts to a shirt and tie between shots.
Oh, Brother, Where Are Thou? - S2-E15
Audio problem: When Homer is praying, he finishes the prayer by saying, "Amen," but his mouth doesn't move when he says it.
Continuity mistake: When Martin tells Bart about the answers being worthless, Bart is stood by the grass or the kerb depending on the shot. (00:04:00)
Audio problem: When Bart's dog is chewing on the TV remote, one of the shots on it is of "I Can't Believe They Invented It." with Troy McClure as the host. This is exactly the same shot from "Homer vs Lisa and the 8th Commandment". You can tell because Troy's voice is different. The lip sync is also out, revealing that the line "As an actor, my eyeballs need to look their whitest" is dubbed in.
