The Witches of Pennbrook - S5-E5
Continuity mistake: When Shawn is saying "So, Rosemary, how's the baby?" his left hand is resting on a box of household items. When the shot changes, his left hand is instantly raised. (00:10:00)
Continuity mistake: When Cory is whispering in Amy's ear, she is holding a cup of frozen yogurt in her left hand. When the shot changes, she is holding it in her right hand. (00:16:40)
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)
Visible crew/equipment: When Eric jumps out of his chair and exclaims "No" during his college acceptance interview, a boom mic can be seen being pulled out of view. (00:19:00)
Revealing mistake: You can tell the ocean visible from the dorm room window is just a backdrop, as there are no waves approaching the shoreline.
Continuity mistake: When Amy is trying to get Alan to back off Mr. Mack, the way her hand is gripping his arm changes between shots. (00:16:45)
A Long Walk To Pittsburgh (2) - S4-E17
Continuity mistake: After Cory finishes explaining to Amy why he loves Topanga, he sits down next to her and begins placing his arm around her. When the shot changes, his hand is instantly resting on her shoulder.
A Long Walk To Pittsburgh (1) - S4-E16
Continuity mistake: After Cory finishes downing his soda, he places the cup on the table. When the shot changes, his hand is instantly away from the cup. (00:16:37)
A Long Walk To Pittsburgh (1) - S4-E16
Character mistake: After learning that Topanga will be moving to Pittsburgh, Cory tries to rationalize their desire to be together for the rest of their lives despite still being so young by comparing their relationship to that of Romeo and Juliet, thinking they turned out OK. Shortly thereafter, he is shown reading the book in his backyard and explains the situation to Mr. Feeny, who advises him to skip to the end to find out what happens to their relationship, much to Cory's dismay. The problem is that Cory already learned the fate of Romeo and Juliet in Mr. Feeny's class in the first episode of the series. He was even dismissive over the idea of a man killing himself over a woman.
Continuity mistake: When Alan is saying "It's a miracle bra, honey, get a camera," his left hand is resting on the table. When the shot changes, his left hand is suddenly resting on his right arm. (00:08:00)
Continuity mistake: Establishing shots of the Matthews' house show the doorknob on the exterior of their front door to be on the left-hand side, but shots from inside the house show it to be on the right-hand side.
Continuity mistake: When Eric is suggesting to Mr. Feeny that they go out and look for women, some shots show Feeny gripping his wine glass, while other shots show his hands down on the table with the glass several inches away.
Continuity mistake: When Mr. Timmer picks up the mini vase, just before Cory tells him to put it down, you can see he is the only one touching it. When the shot changes, Mr. Timmer and his wife are both holding onto it. Cory also instantly has his left arm raised and index finger pointed at the Timmers.
Continuity mistake: When the bartender fills up the mug of root beer, after the foam settles, the mug is a little more than half full. When Mr. Feeny hands the mug to Eric, it is suddenly filled closer to the top.
Continuity mistake: When the bartender fills up the mug with root beer, the foam has instantly settled when the shot changes.
Continuity mistake: When Eric is performing his one-man show, he states in the intro that he was born on June 24, 1978. However, in the season 1 episode "It's a Wonderful Night," Eric fails his test to get his driver's license. That episode takes place during the middle of the school year, but if Eric was born in late June, he would have had to wait until after, or at the least the very end of the school year to try and get his license, as the minimum age in Pennsylvania for obtaining a driver's license is sixteen.
Sixteen Candles and Four-Hundred-Pound Men - S4-E9
Factual error: The match between Vader and Jake the Snake is supposed to be taking place in Philadelphia, presumably the Spectrum, but the establishing shot of the building is actually the Great Western Forum in Inglewood, California.
Continuity mistake: When Topanga walks away upset from Cory, she closes her locker in such away that the bottom half of it is not flush with the frame. Moments later when Cory and Shawn are talking, the locker is fully closed.
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.