HC is correct on this one.
I would suggest tightening up QC all down the Chain but only after a definitive cause can be determined with great specificity and certainty.
Though it will have to draw upon past technical evidence....the perspective should be from a clean sheet of paper by ruling out previous assumptions and perspectives.
These two tragedies of Rotor Heads departing aircraft in Cruise Flight are clear signs that something is being missed in the past investigations and testing.
The results of being unable to find such a certain answer are going to be very detrimental to the future of not only the 225 but to the industry as a whole.