Busted MG-42, yeah. I wonder if the "Hey, don't shoot" show was because they'd ripped off a few rounds and caught the attention of other GI's in a bad way?
An "old" neighbor had shared a similar story with me before I shipped out for S.E.A. He had been in a Blue-on-Blue in the Ardennes because of similar circumstances. I got to see a picture of him getting a Purple Heart from Old Blood-n-Guts.
I'm going to suggest another alternative: He's trying to see of any snipers are around and is raising his helmet to get them to fire at it so that they can locate him.
They'd be piss poor if they bought that, I think. It's clearly a carbine under the helmet. Sniper school in the US taught the men not to go for the obvious ruses. I'd accept a "buck fever" shot, however.
From the angle of the photo it looks like the photographer was standing up and not taking cover. Posed picture?
Or just a gap in the hedge. Notice that the troops in the background have a higher hedge to cover them. It could be posed, of course, but I think the photographer had enough cover to get up a bit. The angle to the ground in the foreground gives me a lens height of about four feet.