They know it's wrong. Like I said for years they ingrained us what war crimes are/were, and I haven't been in long. They always had that caveat that orders don't excuse actions, hence the phrase "lawful order". Now I don't have all the details (obviously) to accurately comment, but shooting an unarmed person is wrong, even if it was aginst a "hostile force" i.e. No ROE needed.
With that said though, these wars aginst guerillas are complicated, with the ROE, and sometimes it isn't clear. However if these are the same assholes I think they are then the reports werethat they were just killing for no real reason or military necessity.