Investigators have had months to measure the moments. But in war, motive is immaterial. The military courts don't measure right or wrong, just whether troops follow the rules. The Uniform Code of Military Justice gives a lot of leeway to infantrymen in combat. Whether their killings are gleeful, angry or calculated, as long as they fit into the Rules of Engagement, they aren't murderous.
I have a question, where do you have evidence of US troops being gleeful about slaughtering innocents? Do you have any? If not did you just add that to imply that as an option absent any evidence?
If not then STFU with that comparison, because it implies that there are such incidents that should be considered.
Man you guys cheat. Losers.