From The Times piece:
It is also because Mr. Obama embraced a disputed method for counting civilian casualties that did little to box him in. It in effect counts all military-age males in a strike zone as combatants, according to several administration officials, unless there is explicit intelligence posthumously proving them innocent.
Counterterrorism officials insist this approach is one of simple logic: people in an area of known terrorist activity, or found with a top Qaeda operative, are probably up to no good.It's hard out there for a vigilante. Just think how George Zimmerman must have felt when he noticed a black kid in a hoodie walking around his neighborhood. As he noted in his 911 call, "there's a real suspicious guy at Retreat View Circle. This guy looks like he's up to no good."