You're right the court may not believe you but let's not confuse the rules of engagement for soldiers in a war zone versus civilian law. Unlike the civilian world, where you can only legally kill in self defense, in a war zone it is possible to have rules of engagement that allow soldiers to kill the enemy even if they themselves are not personally threatened at that moment. I think the pilot truly believed that those men on the ground were insurgents and the pilot superiors agreed with the pilot's assessment at the time and as a consequence didn't court martial or reprimand the pilot. You can argue that the military is not stringent enough in avoiding casualties but I don't see anything in that video that gives me the impression that the pilot did not follow the rules of engagement a the time. If you look at the current military air strike policy in Afghanistan under General MacChrystal you notice that he has greatly limited the use of air strikes in Afghanistan which to me hints that military has learned from it's Iraq War experiences and recognizes the older rules of engagement are counterproductive in a counter-insurgency campaign.