Sectionals - S1-E13
Continuity mistake: In episode 13 "Sectionals" when Will confronts Sue in the corridor about leaking the set-list to the rival teams, Sue is wearing a bag over her shoulder. However, in the shots from behind the bag is nowhere to be seen. (00:16:05)
Sectionals - S1-E13
Continuity mistake: In episode 13 of season 1 (Sectionals), during the five way split screen, the extras behind Mercedes and the ones behind Tina are the same but have different movements.
Answer: The show is purposefully stylized and over the top. It is not designed to be an accurate, realistic representation of American high school. The idea that the glee club is so unpopular other students can literally throw garbage at them with impunity is an over-exaggeration of how glee club is considered "un-cool" compared to things like football. However, there is a second way of looking at it. The audience is simply never shown anyone getting into any trouble for throwing slushies. Just because we don't see it doesn't mean it never happened.
BaconIsMyBFF