Continuity mistake: When Lisa asks for a virgin Moe, Homer's Duff can is missing its colourings. (00:11:10)
Lisa's Pony - S3-E8
Continuity mistake: When applying for the loan, a bell appears on the counter in front of Homer. (00:10:00)
Revealing mistake: When the car arrives at the NFI, the car goes straight through the barrier. (00:09:20)
Continuity mistake: During the Planet of the Apes musical segment, just before Troy McClure sings "Can I play the piano anymore?", he and Dr. Zaius are standing far apart. In the next shot, they are close together.
Continuity mistake: After Phil eats the "horse" egg at Moe's he asks to be taken to the hospital, and when it cuts back to Homer at the power plant, the direction of the stripes on Homer's tie switch to the opposite direction, mid shot. The same thing occurs again later. First, when Homer is standing outside the office while Fred talks to Burns about the benefits package, and also when Homer can't stay for Marge's turkey breakfast. (00:07:05 - 00:12:20)
Continuity mistake: While Homer, Carl, and Lenny are at Moe's with their new bud Fred, in the interior shots the swinging front door to Moe's swings open on the left side, but in the exterior shot when they all leave Moe's, that door still swings open on the left side, opposite to the interior shots. (00:08:00)
Once Upon a Time in Springfield - S21-E10
Continuity mistake: Mr. Burns shows a box of doughnuts coloured pink, brown and light brown. When the guys grab them they're all pink.
Continuity mistake: While Marge and Homer are standing by their front door when everyone leaves the house Marge is wearing earrings, but when it cuts to the closeup both of Marge's earrings have vanished. (00:08:10)
Continuity mistake: After Marge has bitten the candle down to size, when she wipes Bart's face her left earring vanishes. (00:03:35)
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.
The Last Of The Red Hat Mamas - S17-E7
Factual error: Milhouse says he speaks fluent Italian, but his Italian is full of basic grammatical errors. He says that "insegnante" means "masculine teacher" when the same word is used for a male or female teacher. There are errors in Lisa's Italian course too ("barca piccola" instead of "piccola barca"). Despite Lisa's understandable mistakes, as she is a learner, Milhouse never corrects her (there is no such word as "idioto"). Even Milhouse's grandmother, who is Italian, makes many grammatical mistakes.
Other mistake: At the finish line, the crowd are missing all their appearance features such as faces, hair etc. (00:13:50)
Answer: Willy referred to an encounter he believed he had with actual aliens, while Wiggum thought he was referring to the arcade game.