I'm honestly not shocked. The american army, and indeed all the allies, never really had to fess up to or worry about the shooting of German POWs. So, after 60 years of knowing you shot POWs, and being told that it doesn't matter, he prob just feels that it doesn't matter. His feeling isn't the same as all though. I remember one american who told a story about dropping off some POWs with a patrol, and he nearly shot them when he, while relaxing outside the house they were at, heard them shoot the POWs in the backyard. Tempers only cooled when an officer showed up and separated the 3 of them.
And then there was the great story I heard Don Malarkey tell at a reenactment a couple years ago. He pushed through a hedge in normandy to find a German was on the other side of the hedge. They both raised their SMGs and fired, and both magazines were empty. So they nodded to each other and went their separate ways