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.
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: The fictional island of Saint Marie where the series takes place is a British territory - after all, the whole gig is about fish-out-of-water British cops in the tropics. Specifically the Commissioner explains the history of the island to DI Richard Poole driving him to the station the first time and says that it was a French territory but in the mid 70s they handed it back to the British. Despite that, throughout the whole series the police and almost every local drive (on the left) vehicles with French registration plates, specifically with the 971 code of Guadeloupe, where the series is shot. In the first seasons the British police also routinely sends evidence and other critical parts of the job to labs in Guadaloupe, effectively out of the country. Seems quite absurd that in 40 years the British wouldn't have established vital parts of administration and rely entirely on French neighbours.
Factual error: The only person ever addressed as "Sir" is the brigadier, and then only occasionally. No other officers ever seem to be addressed in this way.
Factual error: The British Army soldiers are not wearing British Army uniforms or carrying British Army weapons and some of them have beards, which are not permitted to British Army soldiers.
Factual error: Sergeant Bumpher never wears any rank insignia. He appears to just be a constable.
Episode #1.1 - S1-E1
Factual error: The series is set in 1933, as the initial captions show. Yet the locomotive pulling the Orient Express is a JNR Class C58: the C58 series was built starting from 1938 (C58 239 used here is from 1940).
Episode One - S2-E1
Factual error: During this episode, Vincent is remanded to prison for suspected murder. At one scene he is seen working on the wing. Remand prisoners are not expected or allowed to carry out work duties in British Prisons.
Factual error: Lexy finds Chucky's sneakers by the drapes, and he jumps on her to strangle her, making her drop her joint. That's exactly where the fire starts and grows large, which would have melted his sneakers. Yet in the next episode, he's burned, but his sneakers are as good as new.
The Alchemy Murder Case File 3 - S1-E8
Factual error: The Latin text on the supposedly old tome (which is written with a modern font) displays an alchemist diagram. It is a reproduction of a famous drawing meant to portray the Philosopher Stone in the Sylva Philosophorum, but whoever copied it does not know Latin, because certain words are misspelled ("Merceralia" instead of "Mercurialia", "Humides" instead of "Humidus"). (00:10:10)
Factual error: The show, which is set in California in 1947, mentions the gas chamber, lethal injection and the electric chair as methods of execution in the state. Two murderers are sentenced to death by lethal injection and one is depicted being instead executed in the electric chair, which the governor states has been brought out of retirement for the occasion. In fact, California adopted the gas chamber as its sole method of execution in 1937 (having previously used hanging). Lethal injection was not used in the United States at all until 1982 and not adopted in California until 1993 (becoming the prime method in 1996). California has never used the electric chair.
Factual error: Broken Bow is in the southeastern corner of Oklahoma. US 60 is shown here, but actually cuts across the northern part of the state. (00:09:30)
Factual error: When the stolen freight train is braking, the air pipe becomes disconnected. This should trigger the brakes on the train, but the train keeps going with no brakes. When the train is being slowed with no brakes working, why are there sparks coming from all wheels on the train? (00:32:00 - 00:38:00)
Factual error: Royal uses a pay phone in the library. The only working pay phone in the state at this time is at a rest stop.
The Last of the Cybernauts ...?? - S1-E3
Factual error: When Kane pushes the Range Rover into Gambit, the hand print in the Range Rover's boot looks more like it was made in clay, not the steel panel of a car (which would have simply dented).
Episode #1.5 - S1-E5
Factual error: The senior police officer's name tag reads "Assistant Commissioner" but he wears the rank insignia of a Deputy Assistant Commissioner.
The Murder's in the Mail - S1-E6
Factual error: Dead blonde guy is sitting upright in the chair, as Dave/Maddie close in, and Maddie realises he isn't moving. David goes to him and smacks him across the shoulder, to "wake him up" and blonde dead guy, right on cue, instantly slumps over a table at his right side, when the direction that David hit his shoulder, should have sent the dead guy slumping more forward, then at the front edge of the table. Obviously staged for the actor's comfort.
Song of the Younger World - S2-E20
Factual error: The 19th Century reformatory has modern electric light bulbs hanging from the corridor ceilings. (00:21:10)
Factual error: When Jane is putting up the lost poster, the number to call is 1-800-saw-him. However, this is only a 6-digit phone number when it needs to be 7-digits (not including the 1-800 part).
Chapter Seventy-Nine: Graduation - S5-E3
Factual error: Archie revealed that he joined the Army to avoid repeating his senior year and was shipping to Basic Combat Training the following morning. Before leaving he would need to wait for his background and medical checks to be completed (including getting his dropped murder charge reviewed for suitability), which could take weeks. Also, the Army usually requires a diploma or GED to ship to basic. There were brief periods when the Army was accepting dropouts but it was not when this episode took place.