Emily (a.k.a. The Pink Pearl) - S4-E13
Audio problem: During the scene where John Sears and some of the keg brothers are telling Steve that one of his hazing duties is to steal Professor Randall's signed baseball, pay attention to the camera shot behind John Sears when he is talking to Steve - his lips do not match what he is saying.
Other mistake: When Dylan opens up his locker at school, he only turns his lock dial to the right. (00:06:00)
Ever Hear the One About the Exploding Father? - S10-E20
Continuity mistake: When Jack receives a phone call in his motel room while talking with Dylan, the phone receiver instantly switches hands between shots. (00:13:10)
The End of the World as We Know It - S9-E23
Plot hole: Noah cancels the club's scheduled Monica concert because Dylan pays him to have her give a private performance to Dylan and Gina instead. He seems really excited and proud of himself for some reason. Even if Dylan paid him much more than he would have received from the gate (which is likely), this could cost Noah money in the long run. Many customers would probably get angry and decide to stop frequenting a place that would cancel a concert at the last minute for no good reason. Then again, Noah was never exactly a genius - in business or otherwise.
Character mistake: When David encourages the gang to dance at Scott's birthday party, David mistakenly calls Kelly by her actress' name, Jennie Garth. He says, "Scott, you're off, Buddy. Jen, kind of getting into it."
Other mistake: Throughout the entire 4th series and even various times into the 5th series, pay attention to the shots that show the outside of Steve's Kappa Epsilon Gamma frat house. Every single time, you will notice the same exact two people outside of the frat house - one is a guy wearing a green and white striped shirt sitting in the lawn reading a book, and the other guy is wearing a brown or orange shirt lying on the couch outside. While not impossible, these same exact two characters wearing the same exact clothes doing the same exact things outside of the frat house every single time for upwards of a year or more in 'show time' is unlikely.
Everybody's Talkin' `Bout It - S2-E21
Visible crew/equipment: When Kelly and her mother are having dinner with David and his father at the Japanese restaurant, a boom mic is visible above their heads. (00:18:00)
Perfect Mom - S1-E7
Continuity mistake: When Jackie walks out and Cindy walks in, she closes the door behind her. However, despite the door being closed, Brenda walks in. (00:36:05)
We Interrupt This Program - S7-E18
Continuity mistake: When Rusty leaves the CUTV news room, he has his backpack slung over his shoulder. In the following shot, he picks the bag up off the table and slings it over his shoulder again. (00:16:25)
Character mistake: When he arrives at his hotel room in Vegas, David is surprised that Ray is performing at one of the casinos. But at the beginning of the episode, Steve told Brandon that Ray was performing, which suggests going to see him was part of their plans. So either (1) Steve shouldn't have known Ray was performing there, or (2) David shouldn't have been so surprised.
Senior Poll - S3-E25
Visible crew/equipment: When Kelly returns home after her talk with Dylan, a boom mic is visible above her head. (00:37:45)
Continuity mistake: During the scene in the kitchen where Brenda is at the table and her parents are talking to her about Stuart and then ask her if she wants a piece of pie, her arms are out in front of her on the table at this point. A split second later (same sentence), a rear camera view now has her left arm up holding her chin. A split second later after that when she answers "no", the front camera view now has her arms on the table as they had been all long.
Stand (Up) and Deliver - S1-E17
Character mistake: In one scene Brenda refers to Brandon's political opponent as "Michael Miller" but a few scenes later David refers to the same guy as "Robert." He's referred to as Robert for the remainder of the episode.
Necessity Is a Mother - S2-E10
Visible crew/equipment: Near the beginning of the episode, Brenda is sitting next to a tree talking to the group after Dylan gets up to leave, and a visible mic comes into view hanging center top of the screen.
Leading From the Heart - S2-E11
Visible crew/equipment: At the end of the episode when Brenda is backing out of the driveway, Jim and Cindy are watching her but you can also see someone standing on the porch in the background.
Visible crew/equipment: During the opening scene when the man is counting to 90 seconds there is a mic hanging in the top center the entire time.
Camping Trip - S2-E7
Visible crew/equipment: Dylan goes to the newlywed cabin and Brenda follows him. When she opens the door and says "can I join you" there a mic drop in the center of the top of the screen.
Crimes and Misdemeanors - S8-E19
Continuity mistake: When Brandon is walking Tracy back to her dorm room, her dry erase board on the door says one thing. As Brandon backs away from their kiss, it's a totally different message and the marker is the other way around.
Continuity mistake: In the beginning of the episode Brenda takes her mom's coat to drama class and is wearing a blue shirt and white biker shorts. That night the parents go to the beach club. The next morning before school they show Brenda holding the coat and again in the blue shirt and white shorts she wore the "day before."
Down and Out of District in Beverly Hills - S2-E12
Visible crew/equipment: Kelly, Steve, Andrea, Brandon, and Dylan are all gathered near the lockers when Kelly begins to discuss her opinion of Steve's new girlfriend Christine. Just after Steve says "Tell me everything that's wrong with Christine", the camera pans to Kelly where a microphone becomes visible at the top of the screen. (00:15:15)
Chosen answer: Yes, she was.