Yes I've since learned more. The forensics, pre the coverup grenade, did not conclusively say murder but since a grenade was used to try to cover it up...that pretty much screws over anything that might have been usable in defense regardless.
One realizes there's a conduct code to discourage this sort of thing, but it ultimately that does not stop anyone from acting as we see here.
I'd say it was still a bad call to have the battalion which was attacked take the guy home. May not have been anyone else to do it though. I'm left with a bit of a frown at this whole thing.