Continuity mistake: When Alicia is cleaning up Nick's vomit, she removes her gloves. When the angle changes, she starts removing them again. (00:24:45)
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.
Attack Of The Mutant (1) - S2-E2
Other mistake: In part 2, it was revealed that Libby was really the Masked Mutant all along but, in one scene in this episode, Libby is sitting next to Skipper while the Masked Mutant is standing on top of the bus.
Character mistake: When Olivia and Dr Galina are in the bathroom, Galina mentions an umbilical chord, from a baby whose mother died (Nadia), that contained Olivia's mitochondrial DNA. Mitochondrial DNA comes from the mother, so Nadia's Mitochondrial DNA came from Letha who got hers from Marie, absolutely nothing to do with Olivia.
Heads Of Beef / Klub Katz - S1-E11
Factual error: In "Klub Katz" the captian yells "Iceburg, Iceburg, on the starboard side." But when you see the iceburg and the ship, the iceburg was about to hit the bow of the ship.
Continuity mistake: When Cassie is in the headmaster's office, her red pencil case keeps changing position from being held up clutched to her chest with her folder, to being in her lap.
Continuity mistake: When they first bring the girl to the house with the storm and lay her on the bead the there candles next to her. First the tallest one blows out then the middle one blow out then the shot changes and the middle candle blows out again.
Wuffenloaf - S3-E1
Plot hole: When Abby and Eric return the night vision goggles, Abby asks if they should put them back exactly where they were and Eric says he didn't remember where they went but luckily he "took a picture" of how it looked before. How could this be possible if Abby purposely excluded him when she collected those goggles from Lisa?
Anarchy in Royston Vasey - S2-E5
Visible crew/equipment: When Hilary Briss and Samuel are sitting in Hilary's living room, Hilary says, "Are you alright Samuel? You look a bit nervous." When Samuel says, "Of course I'm nervous." there is a microphone at the top of the screen, above his head.
House of the Rising Son - S1-E2
Continuity mistake: Near the end of the episode, as Klaus is watching Hayley sleeping, Hayley changes from sleeping on her side to sleeping upright in closeup.
Continuity mistake: When the lab equipment shorts out after the earthquake, the unconscious Major Brothers is lying with his head propped up against the wall. But when Hamilton reaches him in the next shot, he's suddenly lying flat and is nowhere near the wall. (00:21:45)
Revealing mistake: The eyes of the actor playing Gideon the robot can be seen through the eye slits of the robot mask in some shots.
Factual error: Sir Malcolm tells Vanessa to wear a facemask when they go to minister to the poor as cholera is rife in the area. However, the series is set in the 1890s and it had been well-known since the 1850s that cholera was caused by contaminated food and water and not by airborne germs. As an educated man, Sir Malcolm is bound to know this.
Character mistake: When Ginnifer Goodwin leaves the supermarket to go the parking garage, the green sign says 1 hour parking Customer's Only. It should say Customers Only, without the apostrophe.
The Battle of Central Park - S3-E6
Character mistake: When Justine Feraldo looks at the checkpoint feeds, she says that the Strigoi have overrun the checkpoint at 116th Street and 110th and Amsterdam. But the feed says 118th and Amsterdam.
Here There Be Monsters - S1-E10
Plot hole: The female police officer has a theory that Johnny was the Strangler in the case the papers claimed he helped solve but this hardly makes sense. If she was researching him as was seen in the episode, surely it would have said something about Johnny being in a coma during the bulk of the murders since the story was about Johnny.
Visible crew/equipment: The boom mike is reflected many times in people's sunglasses, especially Kylie's.
Plot hole: Bonnie is the anchor for the other side and feels when supernatural beings die. How come she didn't know Katherine wasn't dead? Did she never think it was suspicious that she never felt Katherine's body after she died?
Suggested correction: Katherine died but didn't go to the other side. So she didn't need to go through Bonnie. She went to hell to Arcadius. Bonnie is not the anchor to hell, we don't know how going to hell works.
After everyone finally realises that Elena had been possessed by her Doppelgänger Predecessor, It is actually shown that Katherine were more or less dragged away from Bonnie before she could crossover to the Otherside. So we do have some idea as to how one ends up in Hell.
Suggested correction: Katherine was a human technically when she died.
Technically, she was supernatural because she was a doppelganger, so she should've gone through Bonnie.
And even she was a traveller.
Kingdom Come - S1-E6
Other mistake: At the start of chapter 12 in the episode "Kingdom Come," Frank returns home via taxi. In front of his house in Seattle, WA, there is a blonde woman walking a Rottweiler dog. This same blonde and Rottweiler can be seen walking by the crime scene in San Francisco in the "Gehenna" episode.
Plot hole: At the end of the episode when Tommy has change the witches into little statues, he's a werewolf. Then he runs to Stacey and changes back. However, in Hello Nasty it takes a Haiku from Merton to change Tommy back.