A herring gull in the face at 120Kt would easily incapacitate the pilot totally, perhaps doubled over the cyclic pushing it forward and the lever down, or perhaps blinded. The rest I leave to your imagination, but it seems to fit everything we know so far which is more than can be said of most of the theories here.
Agaricus bisporus - how do you explain stopped engines and stopped rotors with the above scenario? If the pilot was incapacitated how could he shut down the engines?
I considered a large bird strike on the fenestron initially but ruled it out due to:
1. The time of night.
2. No evidence visible on damaged fenestron, blood, feathers, bent blades etc
3. It does not fit in with a vertical descent with no engines and a stopped rotor.