“Uh...last I heard those two incidents were cases of U.S. citizens being attacked by an enemy. Exactly which Americans would 0bama order the military to shoot in these circumstances?”
Hypothetical question. Suppose an American Citizen had been one of the 911 terrorists and suppose that citizen was flying one of those airliners towards the World Trade Center. Exactly how would you propose stopping that aircraft without using lethal force against the American Citizen flying the aircraft (let alone all the American Citizen passengers)?
Your question is sound - one couldn't. Mind you, blowing away an airliner full of hostages in order to prevent potential damage at the other end would not be a choice I'd care to make.
I think, though, that Holder was being highly disingenuous by referring to those incidents. The question was clearly focusing on the sort of drone attack used so often in Afghanistan and elsewhere. I hope I'm not being entirely paranoid by reading Holder's answer as "In an emergency the President can blow away anyone he likes."
I think you can bet the eternal salvation of your soul that contingency plans for that scenario do not involve drones.