Helialan may have a good point.
Does anybody know for sure if the crew have actually given their accounts to the AAIB?
The AAIB report doesn't actually say that much that couldn't be got from sources other than the crew.
"Preliminary information indicates that the approach proceeded normally until approximately three miles from the runway when there was a reduction in airspeed accompanied by an increased rate of descent. The helicopter struck the sea approximately two miles west of the Runway 09 threshold." could easily be extracted from ATC information and
"The evidence currently available suggests that the helicopter was intact and upright when it entered the water" could be survivor testimony.
If the crew are not talking yet, perhaps on legal advice, the AAIB could be just as in the dark as the rest of us.
No inside knowledge from me at all, and no criticism of anyone intended, just wild speculation.