Factual error: Wanda's father opens his briefcase of DVDs and one of them is Malcolm in the Middle. But the bomb that killed him fell in 1999, and Malcolm in the Middle didn't start airing until 2000.
Factual error: As the Royal Navy has its own police (including detectives), there would be no need for a civilian detective to be airlifted onto a submarine, especially to investigate a sudden death that was not originally believed to be a murder.
Suggested correction: The Royal Navy police are not equipped to handle murder; local police are usually used for more serious offences so no claim of a cover up. There are no MoD police attached to a submarine either, so in theory somebody would have to go to the boat. (However they still wouldn't risk surfacing).
Initially there is no suspicion of murder, only an unexplained sudden death. There would be absolutely no need to airlift a civilian detective aboard a top-secret submarine. It wouldn't be the first time a sudden death had occurred aboard a Royal Navy vessel.
Power Broker - S1-E3
Factual error: Every guard in the prison has the emblems of Hamburg on his/her shoulders of the uniforms. Zemo is said to be imprisoned in Berlin, so they are wearing the wrong emblems.
The Crossing - S1-E4
Factual error: The Dutton camp as well as Shea Brennon and Thomas are using modern thin Teflon/non-stick coated coffee mugs/pot.
Factual error: Season 2, Episode 1: Two women are diving and need to open an electrical panel. The mother drops the knife she is using to twist off the screws. Her daughter picks up the blade – by the blade and not the handle – and then proceeds to twist the access screws. The screws are on the panel at each front corner. When the panel is removed, there are no front-facing screw holes. All the screws seen are on the inside of the panel to the sides.
Factual error: Bessie says she was going to study veterinary medicine at Texas A and M. That would have been approximately 1940. Neither women nor people of colour were admitted to TAMU until 1963 so she could not have even been able to apply.
Episode #3.2 - S3-E2
Factual error: The navigation software "What3Words" is featured. Apparently the words "flop, sponge, knee" point to a storage facility in London. In reality, they actually point to somewhere near the city of McGrath, Alaska. "Hunch, bumpy, strut" are also mentioned, which actually point to somewhere near Paraburdoo, a town in Western Australia, definitely not a forest in London as depicted in the episode.
Factual error: Three inspectors are candidates for the 'job' of chief superintendent and one is appointed. But British police promotion doesn't work like this. Chief superintendent is a rank, not a job, and inspector is three ranks below it. Officers do not skip ranks. The only possible candidates for a post carrying the rank of chief superintendent would be an existing chief superintendent making a sideways move or a superintendent who could be promoted to the next higher rank.
Family Day - S2-E5
Factual error: The phone number Harry is given has an exchange that starts with "0" (the first 3 digits after the area code). Phone numbers (in the US) can't start with "0" since that's the "operator."
Factual error: The Chief Constable of Dyfed-Powys Police is depicted as a mixed-race woman named Tyler. At the time, the chief constable was actually Terry Grange, a white man. The only woman to ever head the force, temporarily in 2012 (after the period covered by the series), was Jackie Roberts, who is also white. This is a factual series covering real events, not a work of fiction.
Factual error: A passerby tells Sheldon Sampson that the stock market has just gone "tits up." This is a British expression that you would likely not hear in the United States, and you certainly wouldn't hear it in the 1920's.
Factual error: When Alina stands outside of the door to the banquet hall, waiting to demonstrate her power to the king and queen, there is a modern electronic occupancy sensor on the wall behind her.