Character mistake: When the zombies break into Buffy's house, she stakes one to check if it's a vampire. But she should know full well that it isn't a vampire as they all broke into her house without being invited.
100,000 BC - S1-E1
Character mistake: When Ian is trying to escape from the TARDIS in episode 1, he says, "He closed the door from over there, I saw him." It was in fact Susan who closed the door.
Character mistake: Trivette hands the man in yellow a bullet recovered from the plane Walker and Alex were traveling on, which was shot down by an assassin flying a P-51 Mustang. This man, and later Trivette, mistakenly refer to the round as a "50mm," when in reality, Mustangs were equipped with M2 Browning .50 Caliber (12.7 mm) machine guns. (00:30:25)
Character mistake: After Captain Stanley tells the guys about the diet and nutrition study, Cap tells Roy that he and John should go to Oceanside Park for a fire inspection, but later when Johnny's on the HT he tells dispatch to respond Engine 51 to Oceanland Park, not Oceanside Park, and then the dispatcher gives the incident address as Oceanland Park.
Character mistake: When Angus is found dead, he left a word, "murder", in steam on the mirror. Daisy cleaned off the word before anybody, except Laura, could see it. Later, Daisy said that Laura was annoyed with her because she had wiped the words, plural, off the mirror. But it was only one word.
Episode #1.3 - S1-E3
Character mistake: Luther and Ripley pretend they have not been on the boat and did not find the victim's body as they do not have a search warrant and do not want to compromise the case. However, under English law a police officer may legally enter any premises without a warrant in order to save life, prevent injury or protect property. Since they have a reasonable belief that the victim is being held prisoner on the boat and her life is in danger (as far as they know at that time she is still alive), they don't need a warrant. As experienced police officers, they are bound to know this.
Character mistake: Captain Janeway states the temporal differential ratio is .4744 seconds per minute (meaning for every minute on the surface, only .4744 seconds pass on Voyager). Tuvok calculates that 30 minutes on Voyager would be 2 days 11 hours and 47 seconds. However, at that ratio, 30 minutes would be 2 days 15 hours 14 minutes and 15.9 seconds. Later Tom (who was on the surface) says the last two months for them was only 2 days for B'Elanna (who was on Voyager). But with the temporal differential, 2 months on the surface would be less than 12 hours on Voyager. 2 days on Voyager would be almost 253 days (almost 8.5 months) on the surface.
Broken Souls - S6-E2
Character mistake: At the very end of the episode, a chess board is set up wrong, the initial position must have the white queen on the white square (d1) and the black queen on the black (in this case red) square (d8). They set up all the other pieces correctly except the kings and queens should be reversed.
Character mistake: Stabler calls for an LPR check on a vehicle. The description of the vehicle he gives is for white Mazda Sentra. Mazda doesn't make a Sentra. Nissan makes the Sentra. (00:09:45)
Character mistake: The Captain yells to Tex to man the "Fifty cal" but Tex goes to a mounted M240 7.62mm weapon.
Character mistake: In the first scene with Cameron after she walks away from John next to the lockers, there's a poster on a wall to the left. It contains the word "guidance" misspelled as "guidence".
Character mistake: Carrie tells Aayan that she can arrange for him to study at the Royal College of Physicians. The college isn't a medical school; it's a professional body.
Extinction - S4-E1
Character mistake: Happy determines that the nitrogen hydroxide ate through the drum because it was "steel alloy," in contrast with Walter's requirement that it be "pure steel." These terms are inaccurate, and would not be used by technical experts like Happy and Walter. Every steel is an alloy, combining at a minimum iron and carbon; steel with other alloying agents is called "alloy steel," not "steel alloy." Because steel doesn't refer to one specific substance, "pure steel" could never be used to specify a material for a given application.
Green Thumb - S6-E10
Character mistake: When Kim is trying to convince Lisbon to help the FBI on their case, she says Jane stopped the ten-year reign of a mass murderer. Red John was a serial killer, which, by the FBI's definition, is a criminal behavior distinctly different from mass murder; he may have had a large number of victims, but he killed them either one or a couple at a time, with a cooling-off period in between, not all at once.
Character mistake: When Bill mentions to Sophie-Anne that drinking the maenad's blood poisoned him, she says that vampires can only feed off human blood. However, across the show, we've seen vampires drink from fairies, werewolves and even the blood of other vampires, like Lilith's blood. (00:05:50)
Character mistake: In the evening, Emma states that Kathryn Nolan has been missing for 24 hours, meaning that this episode takes place the day after Kathryn disappeared. When Emma investigates Kathryn's car, David tells Emma that he last spoke to Kathryn "yesterday afternoon" (and stresses that he is telling the truth), and that he hasn't spoken to her since he ended their relationship. However, "What Happened to Frederick" establishes that David broke up with Kathryn the day before she tried to leave town and disappeared, because when Kathryn apologized to Regina, Regina referred to the events surrounding the break-up as "what happened yesterday." Emma checks Kathryn's phone records and finds out that Kathryn talked to David on the phone the day she disappeared, but David could not have referred to that conversation, since "Red-Handed" and "Heart of Darkness" both establish that he doesn't remember the phone call because of a memory blackout. Making matters even more complicated is that when Sidney shows up with the phone records, Emma specifically says to him that David told her that he DIDN'T speak to Kathryn that day, which, in fact, he said he did. (00:12:45 - 00:26:45)
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)
Character mistake: Doc holds the binoculars the wrong way round. (00:30:20)
Character mistake: At the end of the episode, after Sarah has been tricked into revealing her plan and is rather obviously going to go to jail, Tru tells her that she "should have taken half," meaning that she should have settled for half of Andrew's money in a divorce instead of trying to get all of it by having him murdered. But Tru seems to be forgetting that Sarah has been trying to divorce Andrew all along, and it's Andrew who has stood in the way of that. Sarah would evidently have been perfectly happy with half, but Andrew prevented it from even being on the table for her, so Tru's comment doesn't make any sense.
Character mistake: Horatio writes the symbols for sulfuric acid, H2SO4, on a clear board. Both numbers should be subscripts but he writes the 4 as a coefficient (which precedes the name of the acid but he writes it after), suggesting a lack of basic chemistry knowledge.