So, whilst none of this is CERTAIN, the board have concluded that Dave MAY have carried out a low level autorotation, misjudged the flare height and ended up at a couple of hundred feet with the lever in his armpit.
How hard is it to judge height above Roof Tops in the Dark?
There are Street Lights and other light sources visible to aid in judging height.
Add that to the definition of angle by looking at building shapes, streets, vehicles (moving and parked)....there is still a lot to see that would aid in determining height.
Somehow I find it hard to accept that the Pilot would misjudge aircraft height by
Hundreds of Feet even without a RadAlt or Landing Light being functional.