Other mistake: After Jack and Rachel tell everyone they broke up and Angela says to Shawn "Friends, okay?", the camera is noticeably out of focus and then comes into focus when Shawn says "Hate you or love you..." (00:05:10)
For Love and Apartments - S7-E2
Other mistake: When Cory is trying to get Topanga's parents to reconcile, Topanga's mother mentions to her ex-husband about the "beautiful child they've made." Given that she says "child" in the singular, this can only refer to Topanga. However, the season 1 episode She Loves Me, She Loves Me Not established that Topanga had an older sister named Nebula. So the mistake is that either the show is acting like a character that was firmly established never existed, or Topanga's mother doesn't realise she has at least two children. (00:15:32)
Other mistake: At the beginning of the episode, Eric talks about how Alan's Navy background will cause him to use any means necessary including torture to find out about his birthday party. Cory chimes in and states that Alan was a cook in the Coast Guard. The plot of the Season 1 episode Kid Gloves concerned a necklace Alan gave Cory for his birthday, which Alan himself earned for placing second in his weight class for boxing in the entire Navy. So either Cory doesn't correctly remember his own father's military background, or the show needlessly retconned it. (00:00:43)
Other mistake: Eric is showing Feeny the doll he has and pulls the string to make it talk. When he makes the doll do mission impossible, he pulls the string but the doll doesn't say anything. (00:03:47)
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.