Continuity mistake: In this episode Eric said he was 8 months older than Jack, but in '5-17 And Then There Was Shawn', Jack said that he was older.
Continuity mistake: When Topanga is in the elevator and is saying "We'll just have to let nature take its..." the elevator door completely closes before she can say "course." When the shot changes to Cory saying "Nature take its what?", the door can be seen sliding closed again.

Continuity mistake: When Mr. Feeny is asking the class if they have any comments on Cory's documentary, he calls on Angela, and Cory begins turning his head to look in her direction. When the shot changes, he is instantly looking at her. (00:04:12)

Other mistake: When Cory goes into the apartment and starts to film Shawn and Jack fighting, he is sitting on the coffee table behind them. When what Cory is filming is shown, the camera is facing their sides, not their back. (00:10:47 - 00:11:11)
Other mistake: As Wendy is leaving the apartment, she writes her phone number on Shawn's palm and tells him to call her. She only scribbled a few lines on his palm for a second, not nearly enough time to write her entire phone number down.
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.