"I've discussed this with a few aviating friends, who, like me, fly from isolated rural strips. We all agreed that shutting the engine down was one of the last things we would instinctively do. "
We're trained what to do if the aircraft stalls (or whatever a gyrocopter might do)....
.... when we encounter unusual attitudes
.... when there's a power failure in cruise
... when there's a power failire at take off
... if there's an engine or electrical fire.
.... if we get lost
.... if we encounter IMC
.... etc
but there's no training on what to do if someone approaches the aircraft. Having the presence of mind to shut down isnt something that would be automatic.