Pubs in England are called by their descriptive name, example: The Nags Head, not 'The Nags Head Pub'.
Heindrich is referred to as "Oberst", which is an army rank, there was no such rank in the SS. The equivalent SS rank was "Standartenführer".
The scene in Holloway prison where the murderess is recruited to the mission, shows her looking out onto a courtyard were a scaffold is erected. Hangings in Britain by this time were conducted indoors in a room adjacent to the condemned cell. Prisoners were not aware of where the gallows was in order to spare them anxiety.
The agents are firing their Stens tens holding the magazine. You would get a stoppage if you did this. The correct way is to hold the barrel shroud.
Heindrich wears the 1936 pattern army officer uniform (green tunic, gray trousers), when as an officer of the Sicherheitsdienst he would've worn the gray 1938 pattern SS officers' uniform.
The film portrays events leading up to the events of D-Day, yet the aircraft parachuting the girls into France displays invasion stripes, which were painted onto aircraft at the time of the D-Day landings to ease recognition of Allied aircraft.