An old Hollywood guy told me years ago that the technical advisors on this film were from both sides. They were put up at some very nice resort and told to just try and remember things.

It was sort of uneasy at first, but then everybody became used to the fact that it was War and nothing was personal about it. Then they all had a great time for several weeks and 20th Century-Fox picked up all their bills.

By the way, the scene where the guy takes the bridge and keeps hearing 'Hold until relived, hold until relived...' The actor that played that part was also the tech advisor on that secne since he was also the same guy that took the bridge that night.