On the raid where Mike gets his fateful injury the bombardier requests they go lower as he can't aim properly. But it's not his call. They are part of a formation, they are supposed to hold formation as a defensive measure and to try and get all their bombs on the same target. Individual planes don't just get to go off on their own.
Various American characters are shown wearing dog tags. The problem is these are the British style fibre disc rather than the metal razor blade shape of the US forces.
After Mike's injury, members of the crew discuss who they will get as a new co-pilot. The dialogue implies its a responsibility they have. It's not. The Army will assign someone.
The prostitute tells David she charges £5 a time. This seems to be a staggering sum. US personnel were well paid. But £5 would still be half a week's pay for a USAAF Captain.
Susan Hampshire's hairstyle seems far more consistent with 1961 than with WW2.