Anyone who wants to approach a running helicopter and get even close to the rotor disc... you don't need to look any further than that for someone to blame. He created a situation where it was dangerous to shut down and dangerous to depart.
Who trains for such an eventuality in the first place? Can you tell me where there is an SOP for this one, dealing with some lunatic under the running rotor? You shut down and perhaps he gets his head chopped off or you lift off and perhaps he makes the whole plot tip over so that the pilot was lucky to get away with no serious injuries or damage. (I bet in the States there would be at least one lawyer specialising in mental trauma all over that rich guy like a rash so let's see what comes of this next.)
We depend on people exercising common sense in the vicinity of aircraft and this rich guy did just the opposite, seemingly losing it and deciding "Right! I will have him!" because of his Chelsea Tractor being littered with grass.
This week a helicopter, next week a bulldozer? It might be doing him a big favour to give him a quiet spell "inside" to think things over, get a reality check so to speak.