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'."
Continuity mistake: Cartman walks into his house and can't remember the code to turn off the alarm, so he gets a call from the security company. When the man on the phone introduces himself, the clock on the wall to the right of shot reads 2:02, then the time changes to 12:37, then back to 2:02 again.
Plot hole: When Cartman is 'confessing his love' to Kyle at the basketball game, the crowd all turn to Kyle and say "Awww" to him. By the time the crowd turn to Kyle, all Cartman had said was that he loves Kyle. No image or live footage of Kyle was ever shown by that point, so how would anyone in the crowd have known who Kyle was or where he was even sitting?