No Such Thing as a Sure Thing - S7-E4
Revealing mistake: When the family is eating dinner, throughout the scene you can see Jack dabbing his fork into his mashed potatoes and raising the fork to his mouth with little to no potatoes on it in order to give the illusion that he is eating. (00:03:57 - 00:05:05)
No Such Thing as a Sure Thing - S7-E4
Revealing mistake: The pitchfork that the Amish girl throws at Eric at the end of the episode is obviously made of rubber, as it wobbles when he catches it.
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.