After Huth is stripped of his medals he still has the Iron Cross around his neck when he leaves the building. In the next shot outside the cross is gone.
When the Wolseley gets a puncture they search in the boot and elsewhere for a jack. That model car was fitted with a Jackall Hydraulic Jack System. The controls would be found below the front passenger seat carpet.
Archer says the Queen and Princesses are in exile in New Zealand. In reality, the King, Queen, Princess Elizabeth and Princess Margaret were to be evacuated to Canada in the event of a German invasion. Hatley Castle on Vancouver Island was purchased for this purpose in 1940.
While the officer is reading the document from the US Embassy demanding Barbara's release, one brief shot shows a full page of text. The text is the same brief paragraph, repeating over and over.
The map showing the airfield says 'MOD'. The Ministry of Defence wasn't formed until 1964. At the period it would have been 'AM' (Air Ministry)