Simpsons Already Did It - S6-E7
Character mistake: Butters says that he watched "all 132 episodes" of the Simpsons; at the time this episode aired, 291 episodes of the Simpsons had been produced and aired.
It's Christmas in Canada - S7-E15
Character mistake: In the first scene, the Broslofskis are lighting their hanukiyah. It is the first night, and the lone non-shamash candle is on the far left side as they look at it. However, Hanukkah candles are placed in the hanukiyah starting from the right.
Two Guys Naked in a Hot Tub (2) (a.k.a. Melvins (2)) - S3-E8
Character mistake: When Pip, Butters, and Dougie play the Wickershams and Decklers game, Pip stated that they all fall down after he says "Ch'rah." However, they fell down after Pip said "Tally-Ho", not "Ch'rah."
Mr. Hankey, the Christmas Poo - S1-E10
Character mistake: When the class are practising the nativity, Mrs Broflovski comes in and berates Mr Garrison for casting Kyle in the part of Joseph of Arimathea, but Joseph of Arimathea wasn't the husband of Mary, Jesus' mother, but a disciple of Jesus who helped in the burial of Jesus after his crucifixion.
Two Guys Naked in a Hot Tub (2) (a.k.a. Melvins (2)) - S3-E8
Character mistake: Before Pip, Butters, and Dougie play Wicker-shams and Decklers, Pip explains that they all fall down after he yells "Ch'rah." However, when they boys are playing, they all fall down after Pip yells "Tally-Ho."
Korn's Groovy Pirate Ghost Mystery - S3-E10
Character mistake: Cartman tells his mother that there are only 72 shopping days left until Christmas. Christmas is 55 days after Halloween.
Character mistake: When Cartman goes to wrap the chain around the locker room door, there are two signs that read 'Boy's Locker Room', one on the wall pointing to the locker room and one on the locker room door. The sign has been written incorrectly; the word "boys" has been written with an apostrophe after the Y, spelling out the word "boy's." In this context, the word is supposed to be a plural, not a possessive, so the word "boy's" should just be "boys." If it were written as a plural possessive, the sign would read "boys'."
Suggested correction: Butters is always shown as being a bit dim and slow. As a kid it's easy for him to make a mistake in thinking that there was only 132 episodes.
Ssiscool ★
That's why it's called a "character mistake"; also, Butters is certainly naive, but he's hardly what I would call "dim and slow."
zendaddy621