"It's not absurd, because the positive tests are all contacts of known cases and the testing rate has been extremely high."
It is absurd, unless every one of those contacts of known cases is and remains isolated before they infect other people. And every new positive generates a new set of contacts who weren't in isolation. Unless they've all tested negative recently (last 3 days) then they're potential new cases.
The outbreak is not under control until the number of new positives is going down. Until then it'll continue to grow and will ultimately shut everything down (except hospitals and vaccination centres) anyway. That would be a much longer and more inhumane virus-enforced lockdown than 7 days now.
Oh - and new case numbers go down on Sundays and Mondays, as testing rates on the weekend are lower than the rest of the week. So expect new case numbers to go up tomorrow (Tuesday) if we're still playing catch-up. If they don't go up tomorrow, the lockdown may helping to reduce transmission.
Andrew Bogut is a former professional basketballer with no knowledge of epidemiology. If he posts something about professional basketball, it's probably worth a read and if he posts about public health management then it isn't.