The Last Of The Starks - S8-E4
Character mistake: Gendry gets declared as Lord Gendry Baratheon of Storm's End by Daenerys. But he refers to himself as Gendry Rivers - the surname given to bastards from the Riverlands. Gendry comes from King's Landing, and bastards from there are called Waters, not Rivers. Given that Gendry is not an acknowledged highborn bastard, he should never have had a surname in the first place.
Character mistake: When Lana and Kit are speaking in the cafe, the window behind them contains a spelling mistake. The window reads "Bolyston Cafe" when it should say "Boylston Cafe." (00:31:45)
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: 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: 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: Winona says that Jason killed a penguin on their trip to the Arctic. This is impossible because penguins only live in the southern hemisphere.
Character mistake: The math test Tina gets a D on has #5 marked wrong. However it is correct. (Additionally it seems improbable she would actually get #3 and #4 wrong since she obviously understood the concept of how to do the problem and only had a problem with the division for some reason, and these questions didn't require division).
Character mistake: A computer display of currency transactions shows the word "withdrawal" spelled as "withdrawl." (It is also spelled correctly higher up on the display). (00:25:05)
Character mistake: Raymond refers to his equipment as EMF (Electromagnetic Fields), except it is labelled as EMR (Electromagnetic Radiation).
Character mistake: In the tent Djem reaches for food with his left hand. Totally a big no-no in the Arab and many other cultures! He would never lean on his right and leave his left arm - his unclean hand free.
G.I. Jessie - S2-E26
Character mistake: In the beginning of the pilot episode, Jessie told the cab driver that her father is in the Marine Corps. However, it is shown in this episode that her father is actually a lieutenant colonel in the Army. It's highly unlikely that Jessie wouldn't know what branch of the military her father was in considering how much she spoke about her military upbringing throughout the series.
Mystery on the Prarie - S3-E14
Character mistake: If Chris and Martin are creature experts, they would have already known the buffalo birds are nest parasites.
Character mistake: Mike is holding and talking about his .59 caliber flintlock and refers to placing a percussion cap on it to fire it. A flintlock does not use a percussion cap.
Character mistake: Iain and Mickey tell paramedics about an old lady needing immediate help in her apartment on the "5th floor" just before stealing their ambulance as the paramedics storm into the building. However, the apartment building has lots of units on every floor and no unit # was given in this fairly large building. Medics would have trouble finding her had this been a real call.
Character mistake: At the start, when Adam messes up Johnny's hair, it cuts from him outside the dining room door to him at the dining room door with no time to sort his hair out but his hair suddenly becomes perfectly done. (00:01:36)
Character mistake: Max enters Brad and Jane's house to find Brad dancing with Santa, Max then calls Brad "Dave." (00:09:18)