Whirlybird: thanks for your interesting summary of the seminar.
I happened to have, on my desk, a note that JAR Part 27.143 says that intervention time (for engine failure, etc) should be assumed as 1 second in the cruise or normal pilot reaction time if greater. It will doubtless be greater if you are hands off the collective and otherwise occupied!
A two-second intervention time used to be widely quoted and was, I believe, the certification basis for a number of helicopters with low-inertia rotor systems.
I could expand on intervention times etc if anybody is interested, but you may have to bear with me until I find my notes with the references. My handwritten 27.143 note is a left-over from a very old thread.
In a previous incarnation I used to demonstrate, as per approved CPL syllabus, engine failures in the climb in the R22, initiated by throttle closure at IAS > 60 Kts and above 200ft agl. Even with anticipation the RRPM was likely to reduce transiently to the flight minimum. It was, I hope, a lesson to both students and instructors alike to keep a hand on the lever in the climb and whenever else possible.
Edit: sorry Whirly, the gremlins (or the firemen?) got your 'Y' first time!