Autorotation
I mentioned this at the time but very few including the AAIB seem to have recognised or commented on it.
The roof that the aircraft crashed on to was a low roof on the south west side of a large former warehouse.
The aircraft final orientation was 90 degrees out from its direction of travel when the engines failed.
The AAIB report states that low RRPM warning come on 3 times.
So after the second engine failed, twice he managed to regain RRPM, albeit at the low end.
He was then I believe faced with a large building and steeple in front of him.
Options, 1. crash into it.
2. Flare
I believe he flared lost RRPM (blades stopping) and then had a vertical descent on the other side of the building onto the pub roof.
From the failure of the second engine to the impact 8 secs later, I don't think many of us could have done much better, at night, over a city. The 'failure to enter automation' comment from the AAIB is harsh in my opinion.
I have tried but failed to attache a google street view to show what I mean but have a look yourselves.