Historically helicopter pilots are not very inventive as they seem to use tried and true methods to do themselves in with great frequency.
True, pruners could save the AAIB a lot of time and money were they contracted as Third Parties to the Investigation but the AAIB is a government organization and thus delights in details rather than conjecture.
After a several decades in this business my experience is the pruners as a whole do seem pretty accurate in their quick draw determination of cause....given a modicum of factual evidence to work with.
After all, poor vis, low ceilings, and a machine scattered over the countryside is not a new situation to many of us.
If one were to add in some wires or darkness or both....then it gets a lot easier for the Arm Chair Experts.
This is yet another tragedy and condolences to those who suffered the loss they did.
This is just another reminder to the rest of us....it can happen to any of us.