Continuity mistake: When Ashley shows Will her weekly schedule, her hand is towards the middle of the upper roll of the parchment, but in the reverse shot where the calendar can be read, her hand is at the top right corner. (00:03:30)
Continuity mistake: When the family kisses Will goodbye and when he sits bummed out on the couch, the pool float around his arm switches position, going under his left arm, then under his right, then left again. (00:02:50)
Homeboy, Sweet Homeboy - S1-E5
Continuity mistake: When Ice Tray announces that Hilary and him got married, Mrs. Banks' glass is suddenly emptier, going back to almost full just a moment later. (00:17:45)
The Fresh Prince Project - S1-E1
Visible crew/equipment: During Will's first introduction to Uncle Phil the camera tilts slightly down to Will and Aunt Vivian on the couch and the boom mic drops into the frame briefly.
Continuity mistake: Will's hat from his school uniform keeps changing from a snap back to a strap-back in each scene he's wearing it. (00:10:00 - 00:13:00)
Visible crew/equipment: The stage lights are reflected on the vase in the family room. (The one with the pink flower design).
Answer: Yes. It's very true. Janet quit at the end of the third season because she claims that Will acted horribly, bullied cast and crew on the set and got her fired for no reason. Alfonso Ribeiro however has called her "cuckoo" and stated that her claims were baseless. He also stated that she was very difficult to work with on set. Even James Avery agreed and often had to remind her that the show was called "The Fresh Prince of Bel-Air" and not "Philip and Vivian of Bel-Air."