How about following the Rules of engagement?
or even the Geneva convention?
They did follow the ROE. That is evident when they didn't "re-engage" the person on the ground, who we know now was a reporter, when he was crawling on the ground. The reason the pilot is saying "C'mon, pick up a weapon.." Is so he can re-engage the man.
That was a terrible event all around, but the pilots were doing their job. They were flying route clearance for the Bushmaster (infantry) element and it was their job to identify and eliminate any threats before they could ambush the ground unit. That's what they did. In that light, you would expect them to be appropriately aggressive. They were under the impression they had identified weapons (AKs and an RPG) requested clearance to shoot and that's what they did.
Now, through the virtue of hindsite and video enhancement, we know they made a mistake and people want to start casting their bony fingers as if the pilots had such benefits during the time.
Before anyone gets on their high horse, every single ******* American is a shareholder in these deaths and all the other innocents that are killed when we send our military into combat. It's not just the soldiers.