I approve of executing any number of people.
In the video, the film goes black before there are any shots. Why?
Once again, there's a dodgy video, unsubstantiated claims, and continuous REEEEing from those who take exception to killing terrorist factions out of hand.
The only fact is the dead civilian. There's no way to go look and see what was happening or discern whether the civilian had anything when he was seen. The helmet camera footage isn't useful at that distance, so the reports of an armed/radio operator are good enough for me. It would be incredibly easy to throw away a weapon or radio in that field.
There's no way to see what happened without comparing everyone's video. So this is yet another REEEEEEing point for anyone who objects to the what's happened in Afghanistan.
Ammunition conservation. If they're closer, you can be pretty certain you'll only need one bullet.