However in todays days of CAR's etc it is becoming illegal to have dual controls unless you are operating a 2 crew environment. Chances of flying with a set of duals in are getting slim to zero.
So in short if a Helicopter pilot becomes incopacitated you will die with no duals in it.
I had this discussion (debate?) with my examiner on my commercial ride. To the best of my knowledge, there is nothing in the CARS regarding dual controls. There is a restriction in the Robinson's POHs (and possibly others) to effect that dual controls must be removed for non-instructional flights with a passenger. However, the POH for my helicopter does not so there is nothing preventing me from leaving my dual controls in place. He called me a few days later to tell me that he agreed with me.
I have let numerous people try the controls in my helicopter. I agree with what has been said here, an airplane pilot *might* be OK in cruise but near the ground they aren't going to make it. With or without dual controls, if I die while we are flying, you are going to die as well