It seems pretty self-evident that a person (presumably not on-duty LEO, non-MIL) would be more effective with a carbine, and (b) unlikely to have access to a carbine during a terrorist attack.
As someone who has a fair amount (very modest by P-F standards) of formal pistol training and is aware of the inadequacy of his purely informal carbine training, I'd take a carbine all day long. Not sure why this is even a question....
I'm curious, where are you going with this?