Plot hole: When the gang is helping Lisa earn tips at her waitress job, Slater says the more people she waits on the more tips she will make. So they take the food away from the customers before they even get to eat it. How in the world would she make 37 dollars in tips with service like that? Horrible service like that would earn her no tips at all.
Suggested correction: I just watched the episode. The group earned $37 in three hours, and Slater was the one who took food away from customers. We don't see how every member of the group treated every customer. Also, it's unrealistic to say no tips at all." Many people will leave a small tip, at least, for bad service. They may think that a portion of tips are going to other servers or the cooks - I worked at a restaurant like that. They may want to insult a server more by leaving an extremely low tip, i.e. one dollar or less. Maybe they usually like the restaurant, and this is their first bad experience there.
Plot hole: Zack was told by Slater that Kelly was excused from going to detention by Belding because Belding found out she saved Screech's life... Yet only 3 students knew about the fake "choking" stunt - Zack and Screech did this stunt to get Kelly into detention (so they wouldn't have said anything), and Kelly unlikely would say anything as generally students will say anything to get excused and usually are ignored by the teacher or principal who use authority to make the student's detention stand. So who else could have told Belding?
