Try this
The pilot used ALT ACQUIRE on the auto pilot at a fairly low level, he was close to the helipad I think.
He was distracted and did not apply power (only 3 axis autopilot).
Helo slowed and then decended and entered vortex ring. Pilot (brain scrambled)
applied full collective. Over pitch etc etc.
Can you stall the blades with both engines working?
He might have shut down the engines before impact. Feds did not say if 'speed select levers' shut off.