Santa's Little Helpers - S6-E11
Continuity mistake: When Shawn and Angela are talking in the student union building, Shawn's scarf is draped around his neck in an asymmetrical fashion, with the left side shorter than the right. When they sit down on the couch, he pulls the two sides to a symmetrical length. Throughout the rest of the time Shawn remains seated on the couch, the two sides alternate between being symmetrical and asymmetrical. (00:15:20 - 00:16:47)
Chosen answer: In the present day, with the United States abiding by more stricter school health laws, for the most part this wouldn't be in school cafeterias as many cannot even have carbonated beverage machines now. However, in the 90s when the show takes place, it wasn't unheard of for there to be coffee machines in the cafeteria of small schools where the teachers eat with the students as we see them do often in the show. The idea being that the cafeteria was small enough so a teacher or hall monitor could catch a student before they could drink the coffee.