I give the soldiers who were there risking their lives the benefit of the doubt in their decision to shoot. If Bin Laden didn't raise his hands to surrender in the first 2 seconds, if OBL made a move toward anything but obvious surrender, split second decisions are part of the deal when you risk your life on a mission such as this one.
So the ethics are misplaced being out of context, not having been there. The Archbishop's position is based on a hypothetical scenario and yet he gives his opinion as if he knows the facts.