Continuity mistake: During 8th grade in one episode, Zack talks to Ms. Bliss about having had to use his sister's bike for a project. In high school, many episodes have Zack being an only child (further proven several times when Derrick Morris would tell Zack that "he and his mother were more important than his job").
Factual error: It seemed like they had several senior years in the show? They had The Prom year when Kelly, Jesse, were there. Then they had senior year when Tori was on the show when they did the senior Class Rings.
Suggested correction: Actually the first senior year was going to be the end of the show. However they wanted to add another season so they had a second senior year and added the new character.
Continuity mistake: When Zack is in middle school, his teacher, Miss Bliss wants to talk to his father. At that time his father's name is Peter Morris and he is an older man and unmarried. When Zack is in high school and Mr. Belding wants to talk to him about the ski trip, his name is Derrik Morris and he has a mother.
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.
Continuity mistake: When the teacher is going through the study fast, you see Kelly stretch her wrist as it hurts from writing so fast. While she is stretching, behind her you see Zack putting on his headphones. A few seconds later the camera is on him and he is putting the headphones on again.
Audio problem: When Violet is singing in front of the audience at the final Glee Club performance, her voice does not match her lips.
The Mamas and the Papas - S1-E12
Character mistake: Lisa is upset about being paired up with Screech. Mr. Belding explains to Lisa that the matches were paired up alphabetically. But this is proven incorrect - although Kapowsky (Kelly) and Morris (Zack) are very close, and Slater (AC) and Spano (Jessie) are even closer alphabetically, Powers (Screech) and Turtle (Lisa) should not have been paired. Assuming no other kids names' interfered with these six (in which case the groups would be different anyway). The correct pairs would be Kelly and Zack, Screech and Jessie, then AC and Lisa according to true alphabetical order last names.
Visible crew/equipment: In the scene where Zack talks to Jessie about switching desks to be next to Kelly, you can see the top of the set for quite a few seconds including lighting, scaffolding and tops of the adjoining rooms. (00:06:15)
Continuity mistake: In the scene where Max has Zack bring Kelly a Coke, you can see the glass only has one straw in it. You can verify that it's simply not two straws stuck together when he lays it on Kelly's table. As he lays it down, the straw swoops around the outer perimeter of the glass and it can be verified that it's only one straw. However, when Kelly decides to take a drink of it there are now two straws in the glass.
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?
Save the Max - S2-E3
Factual error: When Zack is given the old newspaper with Mr. Belding's article, the headline reads, "Picture on pages 3 and 4." When he looks at the picture, he looks at the middle of the paper, with quite a few pages at both sides of the newspaper. Pages 3 and 4 would be near the front and would be on opposite sides of the same page.
Save the Max - S2-E3
Revealing mistake: When they are reading the reviews in the newspaper, look at the back page. It's the sports section. Next when Jessie comes back to Zack and tells him what Mr Belding was hiding, she says the paper is from 1968. But look at the back of that paper also. They are using the exact same paper. The reviews and the 1968 paper are the exact same.
House Party - S2-E5
Continuity mistake: Kelly said her youngest brother can burp his whole name Kenneth Leonard Kapowski in one burp. However in the previous year, Kelly had an infant brother named Billy. According to this info, unlikely Kenneth would be younger than Billy.
Suggested correction: Kelly can have more than one brother because in the episode where Kelly gets her job at the Max she said "I cook every night for my 11 siblings". So he could be younger or just have a nickname.
The mistake is valid because she says her "youngest" brother, not "younger." In the episode "The Babysitters" (which was meant to air in season 1 and produced before "House Party"), her brother Billy is an infant and says his first words. Kelly has 6 siblings and she never said she cooked for 11 siblings when getting a job at The Max. She says she sets the dinner table for 9 people three times a night.
Ironically, the show only reveals 5 siblings each in their own individual episode. (#6 is unknown). Bennett (mentioned), Nicki (seen), Kyle (voice heard only), Kenneth (mentioned), Billy (seen) are the 5 of 6 siblings revealed.
House Party - S2-E5
Continuity mistake: In this episode, Screech's mother kisses her Elvis statue before her trip while it is facing towards the right; indicating that this is the correct way that is should be facing. However, when she comes home after her trip the "new" statue is facing the same direction; right. She complains and says that the statue should always face towards the kitchen so he can see her cook; which is towards the left.
Rent-a-Pop - S2-E7
Plot hole: After the meeting with Zack's "fake Dad", Mr. Belding informs Zack he wrote a letter to see the Dad again... However when the "real" Dad sees the fake "Belding" (whom the Dad didn't know was fake), the Dad never questioned about the "seeing him AGAIN" letter when this real Dad never met Belding before. In addition, wouldn't the Dad question this letter to Zack anyway?
Visible crew/equipment: During the opening credits, as Zack Morris walks into the frame of the school store, you can see the boom microphone briefly lower into the shot up near the EXIT sign on the wall. (00:01:20)
Other mistake: In the scene where the Glee Club is discussing that Violet will win them the contest, Violet leaves as she is upset about Screech. Zack then comments about "No one having a voice like Violet's". If you look at Mr. Tuttle, he mouths the words that Zack says.
Pipe Dreams - S3-E11
Deliberate mistake: When Zack brings an oil covered Becky to the biology teacher, you can see that it's a fake duck.
The Wicked Stepbrother (2) - S3-E14
Character mistake: While holding the fake raffle, Zack says Mr. Belding won't be back for two days. Mr. Belding shows up suddenly, surprising the boys that he's back early - however, at the end of the scene, Slater says to Belding, "we weren't expecting you back til tomorrow."
Continuity mistake: When the group first finishes filming, when everyone says "There's No Hope With Dope!" Zack points his index finger out twice in a row to the cameras, but then when watching the playback of the film, Zack only points once.
