Question: We all assume, as I did when watching the movie, that the opening scene really was intended to be the Malmedy massacre. Could it have been that they were just hinting towards that, and that the opening scene (with the array of mixed Wehrmacht and SS, 101st Airborne and other which is historically not matching Malmedy) was simply another incident? Did the director ever intend to create a grossly false Malmedy scene? There were quite a lot more atrocities in that area and time, with executions of prisoners by both sides.
Question: Why did that guy shoot his own friend near the end? Why did the two start shooting in the first place anyway?
Answer: This movie was based on the Columbine High School Massacre, and another high school massacre. There's no answer to "why" they did it.
Question: At the end when the main character is in hospital, he speaks to a vision of his wife. He says something in Danish, but I can't find a subtitled version anywhere. Does anyone know what he says?
Chosen answer: In pursuit of the answer to your question, I have looked up and found screenwriter Peter Asmussen on Facebook, and directed your question to him. If and when he responds, and if nobody else has provided a translation by then, I will post an update here.
Answer: The massacre was intended to be Malmedy. Artistic license was taken with the participants but what happened is a possible version of events that caused the massacre.
AdmRose