Is this like the Captain of the Concordia, who "accidentally fell" off the ship into a lifeboat and couldn't get back on his ship. If you weren't there how could you know what actually happened there. His subsequent comments that he needed to coordinate the rescue onshore, well?
And if the FO had not regained consciousness? And, her actually finding the exit under those conditions defies the imagination.
We all know how to identify a duck.
Any vestiges of what actually happened lay in the FDR and CVR, both pieces of equipment being mandatory for that VERY purpose, but for reasons that escape me entirely were not recovered. They still may be and it is highly possible they will have recoverable information that will provide some certainty on events.
I suspect Humphrey Appleby might have advised strongly against this, on the age old public service principle of "unless you know what it would reveal don't go there". Since when did cost enter the investigation arena in cases such as this.
It is simply not fair to any of the parties including the pilot.