Factual error: The German pilot held prisoner is wearing a watch that is not correct for the 1940s. His watch is a late 80s / early 90s style watch.
Revealing mistake: At the start of the film, Sergeant Gunn and another member of his tank crew take shelter in a shell hole as they are returning with fuel and spare parts. Watch the supposedly dead soldier hanging over the edge as they leap into it - he visibly reacts and moves his head.
Factual error: The cap badge worn by Captain Halliday of the RAMC is the Queen's crown version, which didn't come in to use until the 1950's. It is also made of brass, when it should be in a bronzed finish for officers.