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.
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: 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: Kendall signs Mr. Bitters' shirt with his own initials "KS", but his character's initials are "KK" for Kendall Knight. (00:02:45)
IMeet Fred - S2-E10
Character mistake: Carly says Shelby, ID Is 4 hrs away. It's more like 11 and a half hours from Seattle.
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: Referring to the US, Russian and Chinese governments, the admiral says that "Washington, Moscow and Shanghai" have been informed. The capital of China is Beijing.
Character mistake: The narrator says, "some trucks were left behind", but only 1 truck was left behind.
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: 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: 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: Doc holds the binoculars the wrong way round. (00:30:20)
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.
Rendezvous with Yesterday - S1-E1
Character mistake: When Tony talks to captain of Titanic he states he was born in 1938, but in episode 4 "The Day the Sky Fell In" it is December 1941, he should be 3 years old, but as a young child he is about 12 years old.
Character mistake: Lt. Joey said to Lt. Sulu "You don't outrank me and you don't have pointed ears" but Joey is a junior grade lieutenant so Sulu would outrank him.
Homer Badman - S6-E9
Character mistake: When Grandpa is putting up the American flag for Homer's public access show and Marge says the flag only has 49 stars, there are actually only 38: 8+7+8+7+8.
Deadeye Dick - S5-E9
Character mistake: Bob's father's name is Harry Foley according to Granger and the end credits. But James Drury apparently forgot this in one scene, where the Virginian addresses Harry as "Tom."
Character mistake: Tom Mason makes references to smaller armies defeating larger ones, of which history is rife with examples. He cites the Scottish defeating 'the British' at the Battle of Stirling Bridge. 'The British' did not exist at that time. The Scots administered a beating against the English in the Scottish War of Independence, against the Earl of Surrey, under Edward I. Someone with his level of knowledge would know that.
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.