Dannyboy:
100%. You can’t shut the world down for one case.
1000 people in the Australian Open bubble in isolation due to one worker case. They clearly wouldn’t have all come into contact within them... probably not even 1%.
Maths wasn't your strong subject at school was it?
You can shut down now for one discovered case for perhaps 14 days, or,
You can ignore that one case for the next two weeks and then shut the whole State down for three to six months while we try to deal with the hundreds of cases that one case has spawned.
Your choice.