If you read the actual accounts of those who were there, you would realize that (while perhaps some) not all were shot on sight when captured.
This is by Private Lowell R. Hollingshead, captured by the Germans and forced to deliver to Lieut. Col. C. W. Whittlesey the German "Demand for Surrender."
"This Officer turned out to be Lieutenant Heinrich Prinz and addressing me in perfect English, his first question was., "How long since you have eaten?" and I replied, "five days." He said, "Poor devil, you must be starved." And I answered, "I certainly am." He then called an orderly to whom he spoke and who hurriedly disappeared. Prinz told me to lie down, but before doing so he gave me a gold tipped cigarette from a box which sat on his table and we were for all the world like host and guest rather than an officer and captured enemy soldier."
So this part of the movie seems to be true to form.
This is by Private Lowell R. Hollingshead, captured by the Germans and forced to deliver to Lieut. Col. C. W. Whittlesey the German "Demand for Surrender."
"This Officer turned out to be Lieutenant Heinrich Prinz and addressing me in perfect English, his first question was., "How long since you have eaten?" and I replied, "five days." He said, "Poor devil, you must be starved." And I answered, "I certainly am." He then called an orderly to whom he spoke and who hurriedly disappeared. Prinz told me to lie down, but before doing so he gave me a gold tipped cigarette from a box which sat on his table and we were for all the world like host and guest rather than an officer and captured enemy soldier."
So this part of the movie seems to be true to form.