Revealing mistake: As the gang drives up to the space-ship diner, cars are whizzing by in the background. When they are driving to the base there's also a clip of a fire truck going down the highway in the distance.
Continuity mistake: When Charlie is climbing down the cliff the rope comes undone from the tree stump, but a few seconds later you see it still tied to the stump. (00:12:00 - 00:12:45)
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.
Revealing mistake: When Brad wears the sunglasses and holds the pole, you can easily see the string that holding it up.
Mommy's Little Monster - S2-E7
Continuity mistake: Miss Kringle's head is canted up and to the right as she lays on the gurney in the morgue refrigerator, but when Edward Nygma pulls her out, her head is facing straight up. Subsequent shots of her in the refrigerator her head is canted up and to the right.
Character mistake: When Henry is speaking to the detective involved in investigating his father's death, the detective says that based upon evidence found at the house he requested a toxicology screen, which showed that his father died of a barbiturate overdose. He continues to explain that he found an empty bottle of hydrocodone in the bathroom trash can. Hydrocodone is an opiate, not a barbiturate. (00:07:35)
Continuity mistake: As the detectives are talking to their captain about the bank robbery, in a shot from behind the captain he takes his hands off his food and clasps them in front of him. The shot cuts to his front as he starts talking, and he moves his hands and clasps them again.
Unreal City - S2-E1
Continuity mistake: While Lieutenant Granderson is being escorted around the compound and walks to the class, she is wearing O-3 rank (two silver bars) on her collar, despite never being promoted during the show to this point. Later on in the episode, when she is talking to her mother, she is wearing O-2 rank (one silver bar) again. (00:13:35 - 00:34:15)
Single Point of Failure - S1-E2
Revealing mistake: Walter accesses code on the sick girl's laptop to trace the source of the virus - aside from the fact that the code comes straight up a fraction of a second after his hands even touch the keyboard, the code displayed in the black window is for a set of traffic lights, with lines like "Walk/Dont_Walk" and "Green_Arrow/Yellow_Slow." (00:08:10)
Continuity mistake: Most of Season 1 takes place in January of 2006, while Season 2 takes place in March of 1979. Molly mentions near the beginning of Season 1 that she's 31, and her father confirms this in episode 10 by mentioning that she was 4 years old during the events of the Sioux Falls massacre (season 2). In season 2, Molly's mother mentioned in episodes 1 and 4 that she's 6. It's also revealed in a flashback scene in episode 10 that she graduated high school in 1991 (most people are 17 or 18 when graduating high school). If you do the math, you'll see that there's an inconsistency in her age between Seasons 1 and 2. Apparently, 2 years were added to her age in Season 2.
Factual error: Educated characters, including an eminent scholar, continually translate 'Lupus Dei' as 'Hound of God'. Even someone with the most basic Latin would know it actually means 'Wolf of God'.
Continuity mistake: When Bauer walks up the stairs in front of Waterloo station, the clock on the building is displaying 1:50pm, however we are only about 8 minutes into the episode. (00:07:50)
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.
Continuity mistake: During the street scenes it appears to be fall with leaves on the ground, grass green and streets and sidewalks dry. However, when police raid the park worker's house there is snow on the house roof and on the ground. When the police stake out the same house, there is no snow on the house roof or ground. (00:36:00 - 00:41:00)
Factual error: Henry states that the car bumper of an 2007 'XJ' is a certain height off the ground and led to a particular injury to a dead person. He claims he knows this because he is a Jaguar enthusiast. He then points to a photograph of the 'New York Kids' in a pre-2002 Jaguar XKR as 'circumstantial evidence' that it was this car that caused the injury. A Jaguar enthusiast would never mistake an XKR for an XJ.
Factual error: Throughout the episode the military are shown carrying Israeli Military Industries Tavor assault rifles. Israel does not sell weapons to any Arab states. Especially if said state already allied with the US and is thus buying its weaponry from the US.
Continuity mistake: While Josh and Cooper are fighting Gabi shouts, "You need to stop fighting.., because you're bad at it and it's embarrassing," then in the next shot the top shelf of the shelving unit is collapsed with nothing on it, but two shots later that shelf is fine with the books, plant, etc, all set up properly. (00:02:45)
The Secret Fate of All Life - S1-E5
Continuity mistake: The first time we see Detective Cohle being interviewed by the other two detectives, two of the beer cans on the table in front of him completely vanish between shots when he asks to see the rest of the discovery file.
Episode #1.6 - S1-E6
Continuity mistake: The district commander wears the rank insignia of a chief superintendent up until the final episode, when he suddenly appears with the insignia of the lower rank of superintendent.
Continuity mistake: When Molly is in space, alone, a man she knew is on The Other Side of a door that has a circular window in it. The man uses his finger to draw the words "HELP ME." When we first see the words, they are legible and about a third of the way below the top of the window, but the next time the words are much higher up and hard to read, and the third time they are now back to the original place.