Continuity mistake: When the princess moves between rooms, the door in the first room is left well open, but when the shot changes to the second room, the first door is almost closed. (00:05:40)
Factual error: Karl Silberbauer, who headed the raid on the secret annexe, wears the insignia of an SS-Sturmbannführer (major). He was actually an SS-Hauptscharführer (senior sergeant). His superior is addressed in German as "Herr Major" (not an SS rank and not how an SS officer would be addressed), but wears the insignia of an SS-Standartenführer (colonel).
Factual error: Both Inspector Shaw and Chief Inspector Bailie wear their medal ribbons in the wrong order. The Golden Jubilee Medal is worn first, followed by the Diamond Jubilee Medal, followed by (for Bailie) the Long Service and Good Conduct Medal.
Factual error: Season 1 Episode 1 Arrival - Doctor Jaax is a Lt. Col. in the US Army. Her BDU blouse has a US flag on the right sleeve. The time period of the show is 1988, as there is a doctor wearing a Dukakis T-shirt. The US Army didn't have a US flag on the BDU uniform until 2005. (00:11:20)
Factual error: The Merchant Navy rank insignia is very poorly researched. Each officer seems to have a different style of insignia, despite working for the same company and they incorrectly wear rank insignia on the shoulders of their blue uniforms as well as the cuffs. The main character, Junior Third Officer Mortimer, wears a bizarre mix of insignia, apparently consisting of a Royal Navy petty officer's sleeve badge, a Royal Navy chief petty officer's cuff buttons, and a rank badge of three inverted chevrons on his shoulder boards that doesn't seem to resemble anything from reality. In reality, he should simply wear a single cuff ring (or shoulder bar in white uniform).
Factual error: Gordon Liddy is in federal prison and in solitary confinement, and he is still wearing his gold wedding band. (00:29:36)