Continuity mistake: In this episode, Cartman discovers Sharon's used tampon in the bathroom bin (which causes Sharon to buy the boys the Okama Gamesphere so that they don't mention it any more), but in season 2's "Spooky Fish", it is indicated that Sharon has started her menopause (Aunt Flo won't be visiting any more) so her periods should have stopped by this point.
Continuity mistake: When Kyle tells Mr. Hankey and his family about the $300 he got for the animated Christmas card, the olive stick in the wife's martini glass is facing to the right. When she says to Mr. Hankey "That's not the only thing we've got to get working again if you know what I mean", the olive stick in the martini glass is now facing to the left. The olive stick then returns to facing to the right for the remainder of the scene. (00:07:50)
Continuity mistake: When the perv runs into the studio (thinking it's a house), he runs into the Dateline show and runs half way down the stairs. However, when he shoots himself in the head, he falls down two stairs. But in the wide shot, he's at the bottom of the stairs. If it was in the middle of the stairs he should be one step higher. (00:19:30)