Shonesum,
Indeed the hindsight is 20/20. What irked me and most of the people is the reaction to the aftermath. There is difference between excuse and reason. Talking about ROE, in that video you can clearly see the soldier talking about how he wishes the wounded 'insurgent' to pick up the arm, so that he could shoot him. How about the shooting of the people who had come there afterwards to collect the wounded people. I have read countless reasons of the possibility they being there to collect the weapon, which you can not say from the video. Equally, the injured children were asked to be taken to 'IP' hospital, which presumably do not have sophisticated equipments as the Americans hospitals do. Not to mention the press release by the Department of Defense, which degraded the human lives and furthermore verified the common belief of impunity to the soldiers. 

The public outrage is justified. However, I am not sure about the perpetration,which to begin with is an occupation.