Here's where I'm struggling...based on known facts..
1 Eye-witness account and AAIB reports state MR and TR not turning prior to, and at point of, impact. (Seemingly no attempt at auto-rotation)
2 Double engine-failure confirmed but post-accident analysis showed engines, fuel-system and transmission serviceable.
3 Fuel in main tank but little/none in supply tanks and filters... and transfer-pump switches off.
4 Shed-bus switch found in "Norm" But restoration of non-essential services following double engine (and thus double generator) failure at lowish level above a built-up area probably rejected by pilot
5 Other similar aircraft in fleet not grounded.
I knew David to be a very professional and cautious aviator and can not reconcile for a moment him not instantly entering auto-rotation the very instant that the 2nd engine failure became apparent... but I am not blind to the fact that humans make mistakes - sometimes as a result of incapacitation .
If and when the AAIB determine the cause of the double engine failure I believe that other questions will remain unanswered.
Regards, TP.