When in doubt, defer to authority -- and by authority, I mean anyone with a "Dr" in front of their name. This has been a running theme of Australia’s response to COVID-19.
The benefit of relying on "the best medical advice" is that there is always an expert who will provide the required viewpoint. State premiers could usually rely on their chief medical officers; CMOs were routinely wheeled out to justify whatever decision the premiers believed would win them the next election. The Victorian government also relied on one or two of its favoured epidemiologists (like Tony Blakely or Nick Scott from the Burnet Institute).
Health Minister Greg Hunt and Prime Minister Scott Morrison are no strangers to blaming their awful decisions on medical advice. Yesterday, Hunt defended the government’s decision to only purchase three vaccines on expert advice. The health minister suggested that the federal government "followed the medical advice and we have followed the advice of Australia’s leading professionals and these include people such as the scientific and technical advisory group".