Whilst being driven to Station HQ at Hucknall, he passes two aircraft on the flight line. The first is a DHC-1 Chipmunk which first flew in 1949, nine years after the film is set and four years after the end of WW2.
At one point, as cover, Von Werra says he is part of the Royal Netherlands Air Force. While this would be correct for 1957 (the year the film was released), in 1941, it would be known as the Dutch Army Aviation Brigade.
The bow of the ship that carries Von Werra to Canada is seen in close-up travelling symbolically right to left across the screen. Unfortunately, the original stock footage was of a bow travelling left to right and the editor just stuck a piece in, reversed. The numbers are mirrored.
As stated early in the film Franz Von Werra had a straight forefinger on his right hand. However, at various stages during the film, Hardy Kruger had apparently forgotten this, as he continuously bends that finger.
When Von Werra crash lands, the cockpit canopy hood on the BF-109 mock-up is hinged on the port side and he exits on the starboard side. All actual BF-109's were the opposite; the cockpit canopy hood being hinged on the starboard side with the pilot entering/exiting on the port side.