Factual error: You can tell that the "Brillo pad" Andrew eats is not real as Andrew would have been VERY ill due to the cleansing chemicals on the pad and the fact that the metal would have cut his mouth considerably. There was no blood, no foam coming out of his mouth (the box says Oxy action implying foam), and he keeps eating despite that the taste would have been horrible.
Factual error: I used to cheer at major competitions like at the end of the movie. These competitons have VERY strict rules concerning music and acceptable moves. Carrie's cheer team would not have been allowed to compete with the song they use and some of the moves they do. They would have been considered vulgar/ inappropriate for their age group and the team would have been immediately disqualified.