Factual error: Ryan, the laboratory technician, eats his lunch of burger and fries while discussing a murder case with Assistant D.A. Claire Kincaid. Trouble is, they are in his laboratory. No lab technician ever, ever eats or drinks in a laboratory - it is the most basic lab protocol imaginable. He could contaminate his samples in any one of a hundred ways, he inevitably contaminates his gloves or fingers with residue from his meal and he risks poisoning himself with accidental transfer. This is not a character error - lab security is hammered into science students starting with the first day of first year and number one on the list is never, ever eat or drink in your lab.
Other mistake: When the show aired in 1990, in the pilot episode Brenda falls for Jason. She later on reveals herself to be a "16 year old junior" in high school. Season 2 opens up with the gang on summer break which technically would make them going into their senior year. It wasn't until Season 3 that they were going into their senior year. They graduated in 1993 from West Beverly but the show debuted in 1990 so technically they should have been sophomores.
The Burning - S9-E16
Continuity mistake: At the beginning of the episode, when Puddy is farewelling Elaine on the street, he is standing on the sidewalk and leaning through the driver's window. The following shot when she pulls out quickly, you can see through the windows of the car that Puddy is nowhere to be seen.
The Fresh Prince Project - S1-E1
Revealing mistake: When Will staples his Malcom X poster to the wall, the wall bends back and forth for a second or two.
Episode Nine - S2-E2
Continuity mistake: The necklace James took from the coconut in Dr. Jacobi's office in the previous episode had a gold chain. When he gives it to Agent Cooper in this episode, it's on leather.
Revealing mistake: A minute or so after the health and fitness instructer dies, we see her lying flat out on her back. If you look carefully, you can see her chest moving up and down and breathing despite being dead. (00:13:05)
Suggested correction: If you actually watch the whole episode you will find she didn't die at all.
Talking rubbish I think, she did die. Maybe you're confusing her with the old lady who fainted?
At what point in the show did they reveal the instructor didn't die? It was the old lady who had just fainted.
I'm a big fan of this comedy and have probably watched each episode 20 times! I struggle to recall any mention of the fitness instructor not being dead.
The Father Christmas Suit - S2-E11
Revealing mistake: When Elizabeth is driving Richard's car to the church dressed in the father Christmas outfit with Hyacinth you can see that the handbrake light is on while the car is supposedly being driven.
So Long, Frank Lloyd Wrong - S7-E7
Continuity mistake: When Joe and Helen are talking to Y.M. Berg, there is someone at the AeroMass counter that is seen leaving twice.
Continuity mistake: When Gussie is telling Jeeves & Wooster that he gave the notebook to Sir Watkyn, in one shot, the scarf on Wooster's head changes from being wrapped around his neck to draped loosely on his head. In the next shot, it's back around his neck. (00:36:40)
Character mistake: Bobby gets injured in a racing accident. When the family is told by Greg that Bobby is paralyzed and can't walk, Marcia starts to smile, then quickly changes to a sad face to match the situation.
Dreams, Schemes and Putting Greens - S1-E4
Audio problem: When Maurice exhales at the end of his sentence as he protests the Japanese businessmen walking out of his house, the sound of his exhale is spliced off mid-way through. (00:38:55)
Life's Ruff - S1-E20
Continuity mistake: In the last shot at the Florida State Poochitentiary, Herman's hat goes from white to brown. (00:08:44)
Character mistake: Jessie's dance moves don't match what the other girls are performing, even though it's a choreographed routine.
Polly Wants a Treasure - S1-E8
Continuity mistake: In the scene where Baloo and Kit walk through the Sea Duck's cargo area to try and find who they think is a stowaway, Baloo lifts a crate of fragile crystal glasses over his head. The crate rotates between shots, judging by its red "Fragile" stamp.
Continuity mistake: When Randi is in her tent working on her thesis, the computer is on. When something hits the tent, she almost drops her computer which now has a black screen, indicating that it is off. When the werewolf rips through the tent, the computer is now back on.