Gentlemen
I've followed this thread with great interest, both from the point of view of an old and bold aviator who once flew helos around that area of the UK; and now, as a lawyer.
You can speculate as to the cause of this terrible accident until the cows come home. The issue now is the proper application of the correct legal test that applied at the time - that is "no doubt whatsoever".
Certainly, if one applied the civil test of "on the balance of probabilities", or possibly even the criminal test of "beyond reasonable doubt", some blame might attach itself to the pilots. But on my reading both of all that's been put here, and elsewhere in the public domain, I think that the admissable evidence doesn't quite measure up to the "no doubt whatsoever" threshold.
That might offend some here who argue from their own aviation experience that pilot error caused this terrible accident; because in their view, no competent pilot would have done what the pilots of ZD176 allegedly did that day. Maybe, but there's still some residual doubt, and in a country that adheres to the principle of the rule of Law, the deceased crew are entitled to the benefit of it.