Again, if someone takes their gun ownership seriously enough to get a carry permit, and they are incapacitated by anything, they are not going to pull out their gun. I am talking about allowing permit holders to carry on the airplane, not just anyone. Different mind set entirely.
Here's a random thought, though--if an air Marshall is called to spring into action on a flight, how do they usually make sure they're not mistaken for terrorists themselves? I, at least, would flip out and throw my stinky blanket into the face of anyone brandishing a gun on my plane.
I am not an air marshall so I don't know their procedure. "Brandishing" a gun is probably their last resort. If an air marshall were to get out of their seat to deal with someone I doubt (but I don't know) the first thing they would do, before proceeding down the aisle, would be to pull out their gun. They might have their hand on the gun, but I doubt it would be exposed. I also doubt that air marshalls, physically, fit the standard ME profile.
Of course, if someone with a gun is incapacitated on a flight, who knows who might pick it up?
Aren't wild card arguments and conjecture fun? :D