Factual error: The Columbia paramilitary is seen throughout the 2nd season carrying M4's. The M4 configuration of the M16 was not available during the period Norcos took place. In one seen in fact an M4 has an EOTech optic mounted on it...backwards. Not only is the optic backwards, EOTech was not founded until the late 90's or early 2000's.
Factual error: The detective constable is addressed as "Sir" by uniformed constables. They actually hold the same rank. Detectives do not outrank uniformed officers in Britain.
Factual error: The Mitanni king and his son are depicted as black Africans. The Mitanni originated in the modern Iran/Iraq area, or possibly as far east as India, but certainly nowhere near Africa. They were definitely not black Africans.