On the security guard thing....I am more interested in why it didn't work in two hotels but 10 others seemed to be ok. What were the differences in procedures and controls, if any? The answers would be illuminating to me. Was there a single lapse or several?
Same with aged care and hospitals....why did only some care centres get cases? Why were some able to contain them? Why did it go completely off the rails in others? In private groups that were cutting corners across multiple sites why didn't every one of their centres have breakouts ie how did some get through without nurses and PPE?
It comes down to who gets infected, some people become super spreaders due to their own personal circumstances and physiology I guess. There have been quite a few articles from epidemiologists talking about this. Clearly infection control also plays a large part but it is possible that a person gets infected and doesn't infect anyone else. IMO the decision on the security guards is almost completely irrelevant, infection control and contact tracing were the major factors, and they go back to DHHS being a basket case for a long long time.