The Kipper and the Corpse (a.k.a. Death) - S2-E4
Character mistake: When Sybil is telling Basil that the two men and the woman are coming to collect Mr Leeman but he's already pronounced dead, she tells her husband that they are coming to collect him "at lunchtime". However, his colleagues told Mr Leeman they'd collect him at 9:30 and not lunchtime.
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.
Character mistake: When all the wives are in the van Lois calls Bonnie "Debbie".
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: 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.
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.
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.
Character mistake: Bailey says that Princess Xaria perished before she ever got to see her crown; but when Xaria possess Bailey later, the spirit says she wore the crown to prom.
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.
Just Stuck It in That There Doo-Dad - S3-E3
Character mistake: At the start of the episode, Jimmy says he met Cookie at work. The scene then changes to the strip club where Cookie is working and Jimmy is there looking for Bobby. In the Season 1 episode "The Horny Bastard", Jimmy tells Cookie that they met when he robbed her dad's liquor store.
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: 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 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.
Character mistake: Doc holds the binoculars the wrong way round. (00:30:20)
Character mistake: Upon hearing that Lister, Kryten, Cat and Rimmer have travelled from Albion - England - to India the woman in the market expresses surprise that they have travelled "halfway across the known world" just to buy lemons. In 23AD travelling from England to India was all the way across the known world. The Americas, Australasia and China were completely unknown at the time.
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.