Factual error: It's Christmas Eve 1925. Tommy and his son leave a mince pie for 'Santa and Rudolph', but there was no reindeer called Rudolph until the 1930s. The character's author hadn't even graduated by 1925, and only began writing a book about a red-nosed reindeer in 1939.
Continuity mistake: Charlie, Olivia's former partner and friend in the FBI shows up in this episode during the interview with Mrs. Rusk, but Charlie was killed off by one of the shapeshifters in a previous episode, and the shapeshifter that killed Charlie was himself killed off by Olivia, who in other episodes reflected back on killing him. This episode was supposedly meant to be in season 1 as ep 21 or 22. Unknown why they didn't air it then, and decided to put it in the middle of season 2 (for no apparent reason).
Continuity mistake: When Jax and his crew meet up with a Hispanic gang to sell them guns and are outnumbered, they run in the station wagon. The run the station wagon through a gate and roll it, destroying the front end, but magically the station wagon's front end appears with little damage afterwards. (00:27:15)
Episode #1.8 - S1-E8
Factual error: When the bullion van leaves the yard a 1995 N reg Rover 600 is parked on the left hand side of the road, before Ray drives off in his Granada. In 1982 the Rover 600 was not even on the drawing board.
Mercy Moment Murder Measure - S1-E7
Factual error: Early in the episode, there is a long shot of Woodhull's farm, snow on the ground...and aeroplane vapor trails in the sky.
Guy Walks Into a Psychiatrist's Office - S2-E1
Plot hole: In this episode Tony tells Janice that he has just put their mother's house on the market. In season one, the house had already been sold.
Suggested correction: Tony and others say many things that aren't accurate. While season one gives the firm impression that the house is sold, it's not confirmed on screen. There may have been a deal where the intended buyer couldn't get financing or a closing never took place for other reasons.
Plot hole: If Noah could be brought back from the dead with Claire's blood why couldn't they bring back Nathan? Was turning Sylar into Nathan really the first thing they could think of?
Continuity mistake: When the Hulk throws the tire during his second transformation, the first shot shows a horizontal trajectory but the second shot shows a 45 degree angle trajectory, which makes the tire land much further than expected.
Continuity mistake: Chase gives Zoey a radio in this episode, but in 1-3 Webcam, when Zoey, Quinn and Nicole are in Zoey's room trying to figure out who is telling the girls' secrets to people, you can see that radio above Zoey's head.
Continuity mistake: The age gap between Eric and Cory decreases as the series progresses. At the start of the show, Cory is in 6th grade and Eric is a high school sophomore, meaning they are four years apart, give or take a few months. By season 3, Cory is in 9th grade (confirmed by dialogue mentioning that Shawn, who is in the same grade as Cory, is 15 years old), and Eric is a senior, leading to an age gap of three years. The first episode of season 4 takes place a couple months after the end of season 3, with Eric and Cory returning from a summer Road Trip, but just two episodes later, Cory mentions that he is in 11th grade, while Eric is still barely out of high school, leading to an age gap of two years.
Continuity mistake: In season 1 they are tracking leopards but when they take a cub for the cure it's clearly an African serval kitten.
Continuity mistake: During the photo shoot, after Tony takes the final shot and tells Margaret to "get dressed", so he can show her his place, she is wearing a different blouse and different earrings when she comes upstairs to his apartment.
Audio problem: When Michael is forced to do "errands" for Brennen, they stop by Jonathan Carver's house to get numbers from him for a voice key. The code played back at the facility is 71348. He says "3" in a medium pitch (tone) at the house, but it is high pitched when played back at the facility; he says "8" in a medium pitch, and it's also high pitched later. And finally he says "9" in a low pitch and it's played back medium pitch. Also very obvious is the fact that Jonathan never says "1" or "7."
Continuity mistake: When Allison gives Kurt his breakfast muffin (in a brown paper bag), it suddenly jumps from his left hand to his right hand between shots.
Revealing mistake: (Part 4) After Omega takes off his mask and looks in the mirror, when he sees that his physical body doesn't exist he puts his mask back on and screams, but when he shouts, "If I exist only by my will, then my will is to destroy," Omega's mask pops up off his face, and we can see the actor's blackened face as he shouts the last bit of his dialogue. (00:07:10)
Chapter One: The River's Edge - S1-E1
Revealing mistake: When Hermione opens the bag of money, one stack says "Motion Picture Use Only." (00:29:45)
He Lokomaika'i Ka Manu O Kaiona - S8-E20
Visible crew/equipment: You can see a crew member's arm below Junior while he is trying to climb the side of a cliff. (00:18:30)
Factual error: Sierra Nevada beer would not have been available in DC during this time period.
Continuity mistake: When Crockett tries to stop a rapist in a white Lamborghini the Lamborghini's taillights switches design during the chase.
Visible crew/equipment: During the final chase, Jaclyn Smith's double stuntwoman is extremely evident. (00:43:45)