The Best Kept Secret in the helicopter industry is how critical it is to immediately apply aft cyclic the moment a loss of power to the rotor system is detected.
The transition from normal stable flight to stable autorotation flight has always been a messy affair requiring the application of lots of inputs quickly. Nr drops, nose drops, nose yaws, body rolls all of which must be fixed quickly and it can be fixed easily enough. We tend to generalise this maneuver when we talk about it by only mentioning lowering of the collective but what we really mean is going from one mode of flight into another. I'd like to think this wasn't a secret to this experienced pilot.