Geeeze, fellas, what would the High Court of Australia (HCA) know, compared with the views on the law as expressed by some of you here.
Just for a start, there is no such thing as "absolute safety", and that has been recognized by the HCA. Risk Management standards such as (but not limited to) ASNZ 4360 only go back to 1999 or so. Long after 1982.
Amendments to the Trade Practices Act, to recognize the legitimacy of high risk commercial activities is far more recent than 1982. The whole thrust of HCA judgments, and considerable bodies of legislation, have changed radically (and for the better -- reintroducing personal responsibility for personal behavior, as but one example) since 1982. Although in an entirely different area, recent HCA judgments effectively disallowing certain aspects of NSW OH&S legislation ---- legislation that implied absolute safety is achievable ---- are relevant.
In short, a decision by CASA, based on current legislation, that E over D is what is required in Broome or Karratha, in that it satisfies the risk management criteria as embodies in the airspace regulation,ie: the minimum classification that meets the separation assurance criteria, is a lawful decision.
Such a decision (if the processes have been correctly applied) would not be found to be negligent, because of claims by some that "C over D is safer". If you understand the legislation, (remember it is no longer up to Airservices and their rather strange internal risk management system, as it was with the NAS 2b rollback) all OAR is doing is as required by the Parliament --- they are not making
personal judgments about airspace classification ---- but complying with the Airspace Act 2007.
In this respect, it is very similar to the "new" Design, Certification and Manufacturing Rules, where and unlike pre. 1998 rules there is no "----- and CASA is satisfied". Neither CASA nor its employees can be found negligent for following processes laid down by Parliament --- if they have properly followed the processes.
If you want to sue Parliament for alleged negligent regulation --- good luck.
Tootle pip!!
What is being argued is As Low As Reasonably Practicable i.e. Safer C for the cost of E, not as you wrongly suggest, 'absolute safety'.
ARFOR,
I rather think you are referring to ALARP as embodied in the Airservices SMS as per the NAS 2b era, that no longer applies ---- ALARP as a concept is still with us, but in proper risk analysis, it does not mean quite the same thing as during the period prior to the Airspace Act, and as applied by Airservices.