This spinning need not occur...Placing a crewman on the ground with a tag line attached to the litter and played out lateral to the helo allows for countering the rotation from rotor wash...
Once the litter is on board the helo, the ground crewman can also be recovered...
Issue is one of procedure...
I've wondered why there can't be a system of vanes on the litter to, at least partially, counteract the turning force of the rotor wash.
And who keeps him from spinning?