Much speculation and opinon from both sides (those who are certain, on the basis of no evidence, that they know what happened, and those who in the absence of evidence believe it unlikely that the full facts will ever be known).
However, at least there is now conclusive written evidence for the fact that the aircraft was not airworthy, many of its systems were suspect, the release to Service was fraudulent and Air Rank officers responsible for that were demonstrably guilty of gross negligence.