ST and JE,
I'll happily agree with you for single pilot operation with awkward speed selects in the roof etc. And sure, twin pilot requires a switched on P2!
Certainly for twist grip I maintain that you are better off chopping the throttle. SASLESS's example explains why. Unfortunately in his case the driver forgot the 'cushion' part!
FB
says, if you donīt dump the collective immediately, you get a very high rate of rotation, which increases the risk of being killed.
FB, IF you close the throttle, the rate rotation stops accelerating, and starts to slow. Only now, you still have the ability to cushion.