
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: Detective Superintendent Hamilton has red fabric within the crowns on her rank insignia. This would be correct for most British police forces, but the Metropolitan Police uses blue fabric instead.

The Girlfriend Experience - S3-E8
Factual error: The group set up a sting for prostitution/solicitation, even though it isn't illegal in Canada. The unnamed city they patrol is Canadian, established in the "sister cities" they name, plus often referring to Rochester and New York as "across the border. As for prostitution, the only two times its illegal for adults in Canada is public solicitation (street walking) which doesn't apply for websites, or in running bawdy (cat) houses, neither of which apply here.

Factual error: When the cops need to arrest a medical professional, they are frequently shown barging into his/her office, exam room, or even operating room. This would never happen in real life and is strictly forbidden, as it is a gross violation of the patient's privacy, and in the case of the OR, could contaminate the sterile environment, thereby jeopardizing patient safety as well.

Factual error: ACC Pat Gallan wears the ribbon of the Queen Elizabeth II Diamond Jubilee Medal. The medal was issued in 2012. Her medals would be correct for 2017 when the series was made, but not 2007 when it is set.

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.

The Hoodlum - S4-E1
Factual error: Diamond's car phone, quite a rarity in the 1950s, attracts a lot of attention. But the car should have a huge antenna attached to make the gadget work (it doesn't), and Diamond would not be getting direct calls - they'd have to go through a mobile operator first.

Running with the Devil - S1-E2
Factual error: The show is set in 1982. However the dedicated song on the radio is Mötley Crüe's "Shout at the Devil", which wasn't released until September 1983.

Factual error: At the beginning of the episode, Patrick Swayze is looking at photos of two Iraq veterans who have been murdered. He identifies one as a Marine Lance Corporal and the other as an Army PFC, but both pictures show men in U.S. Army uniforms. A bit later, his partner, who is supposed to be a Marine vet, refers to his decision not to "re-up," using the Army term for re-enlistment, rather than "ship over," as it's referred to in the Navy and Marines.

Factual error: The gun used to kill Koresh is a Beretta M9A1 (92A1). These were not produced until 2006. The correct pistol would have been a Beretta 92. (00:43:15)

One Watson, One Holmes - S3-E19
Factual error: In the scene in the hospital, the guy who drove his motorbike into a van has an IV canula in his right hand, but the IV pole and the IV bag are on the left side of the bed, which means the IV line has to be long enough to go up to the bedhead, then behind the bedhead and then up to the bag, leaving no way to check for air bubbles.

Factual error: When Tara goes into her office there's dried blood on the carpet from her faked miscarriage. Considering it's a bio hazard that happened days ago it would've been cleaned up and sanitized since it's a hospital.
Suggested correction: The blood is on carpet which is very difficult to clean as it's such an absorbent material. The carpet will keep the stain, but as long as it has been thoroughly sanitised there is no issue here. Yes, the carpet could have been replaced, but hospitals don't generally keep spare carpets laying about. Plus the fact that her office isn't a treatment area, there isn't much of a hazard anyway.
Doctor's office with a blood stain on the carpet? Highly unlikely.
Highly unlikely doesn't make it a mistake.

Episode #1.5 - S1-E5
Factual error: Catherine is told she's been recommended for the Queen's Police Medal for Gallantry. This has not been awarded since 1977, when it was replaced by the Queen's Gallantry Medal, which is still awarded.

Revolution 1 - S2-E4
Factual error: Hodiak is having breakfast at a dinner. There is a sign for breakfast with a price of $4.95. In 1967 the price for breakfast would have been around $1.25 or less. Minimum wage was $1.60 an hour and the price of a big Mac, for example, was $0.50 and fries $0.10. So a $4.95 price for breakfast is just ridiculous.

Factual error: Wilshire Grand Center is visible in the skyline, but it was constructed starting in 2014, 10 years after the murder. (00:51:09)

Factual error: Throughout the series and credits, the ranks of Detective Superintendent and Detective Chief Superintendent are abbreviated as DSU and DCSU instead of the correct DSI and DCS.

Factual error: When Walter Goggins fires a LAW at the church from next to the vehicle, the back-blast from the rocket would have shattered the car's windows, and flying glass fragments would likely have injured the occupant. The show depicts neither outcome.

Factual error: When the tracking dog finds a gun in some bushes, Kenda, who is narrating, says that the gun was a Ruger Mark I, which is a semiautomatic target pistol; but the gun shown in the reenactment is a snub-nose .38 Special revolver.

Factual error: Paul tells Shea that he has a condition called Sporadic Fatal Insomnia. Later, Shea finds a fork in a bag labelled Abby. Paul explains that Abby is his daughter, and he wants to test her DNA, because she has a 50-50 chance of contracting the disease. This is false. Sporadic Fatal Insomnia is not hereditary. Fatal Familial Insomnia is genetic and is the inherited form.

Dial Margaret for Murder - S2-E4
Factual error: In Series 2 Episode 4 (Dial Margaret for Murder), Allison listens to Dick Frank's heart. She has her stethoscope in her ears backwards. As a physician, she would never do that.