Disembarking with spinning rotors is idiotic but I don't see how jacking up a skid would damage the rotorhead. It obviously is fine when the rotor is still, and it obviously is fine when the rotor is spinning at flight speed because slope landings and especially full-down autos (or hover autos) results is significantly greater shocks to the system. So is there some magic point where the rotor is spinning, but relatively slowly, that somehow makes the rotorhead subject to damage? If it's a reference to ground resonance, that's not an issue with Robinsons.