Cattle Truck,
If I thought I was running out of Fuel....the last thing I would do is turn off the Transfer Pumps and Turn on the Prime Pumps. I would want the Pumps to transfer every bit of fuel they could....and they can only do that while running.
I might turn the Prime Pumps On having left the Transfer Pumps on....but I doubt the Prime Pumps would do you any good as the Engine Driven Pumps would pull whatever fuel is left. The Prime Pumps might help if you got a burp of air then more fuel but i doubt it would do any better than the Engine Driven Pump.
As to pulling off all the Rotor RPM as a result of picking a bad spot.....given the pavement and open areas including a River in the area of the Pub....a Pub Roof is the exact last place I would have picked for an EOL.
Have we determined the approximate location of the aircraft when the Fuel Low Lights would have illuminated and if a safe landing area had been over flown after they had come on?