Visible crew/equipment: In the hotel room with Brenda and Dylan, right before he picks her up and puts her over his shoulder there's a mic drop in the top right corner.
My Desperate Valentine - S2-E16
Other mistake: At the end of the episode Brandon mentions he dropped Emily off with her parents and spoke to them. In season 4 when he goes to look for Emily at her parents' house in San Francisco he asked the woman who answered the door if she was Mrs. Valentine, as if they had never met.
Class of Beverly Hills - S1-E1
Factual error: In this debut episode of the show, Andrea takes a bus home to "Van Nuys." After showing the bus heading to the valley on the 405 freeway, as she exits the bus, the street sign states "Gramercy Pl" which is in L.A. (not Van Nuys or the San Fernando Valley where she is supposed to be in). In addition, her house shows 548 to be the address. All addresses in Van Nuys are either four or five digits.
Continuity mistake: In season 1 episode 12 while playing ouija board Brenda says she "doesn't know any dead people", but in this episode it's revealed that her aunt died 2 years ago from cancer.
Summer Storm - S2-E3
Visible crew/equipment: A mic drops into view when Brandon asks Kelly who she is looking at while she is staring at Kyle.
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."
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."