Gaffes

When Ella and he companions escape from the prison, they drive off in a right hand drive car, normal for the UK but not for Germany.

In the opening scene the bus conductor announces that the bus is stopping at 'Westminister' Bridge.

Toward the end of the film, in the scene just before the bombing run, a woman tells Dietrich 'The RAF ... they're right over us!' However in the subsequent views of the aircraft flying, one can see white stars on the fuselage of the planes, signifying American aircraft, not British. The air forces of the UK used an identification mark called a 'roundel,' usually a red disc surrounded by white and blue (sometimes gold) circles.

The gun that Dietrich takes from Mrs. Muggins has no firing trigger.

When Ella goes to clean the windows in Karl Dietrich's office, the shadow of the boom microphone can be seen moving up the wall to the left of the window.

The title on the door under Karl Dietrich's name - Sturmfuehrer - was the lowest commissioned officer rank, equivalent to a second lieutenant. It's inconceivable such a low-ranking officer would have such a large office in the Reich Chancellery next to Joseph Goebbels' and Heinrich Himmler's. Additionally, that rank was obsolete after 1934 in the SS, and the character wears an SS uniform and collar tabs of a Standartenfürer - the equivalent of a colonel.