Since when have aviation incident investigations by ATSB/BASI etc been confined to "airworthiness issues"? I could have sworn that there are these things called 'the rules of the air', enshrined in the civil aviation rules, compliance with which has some benefit for aviation safety. Since when have the local coppers been trained in the rules of the air, radio carriage and use rules.etc?
Unsurprisingly, RAAus wanted the good bits of 'self regulation' but didn't want the bad bits.
(And BTW, what the ATSB says about what it is "responsible" for is self-serving and inaccurate.)