Cabinet's decision to flag a move to level 1 outside Auckland in seven days' time is its riskiest move yet and seems out of step with its cautious approach so far.
That doesn't mean it's the wrong decision but, as Professor Michael Baker says, it's a calculated risk that may or may not come back to bite.
And that's a line Cabinet has been unwilling to walk so far, which begs the question of whether any politics is at play.
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A move to level 1 - where life is normal beyond border controls - is predicated on a super minimal chance of Covid-19 spread in the community.
Concerts, weddings and indoor singalongs can all go ahead without any social distancing or limits on numbers. These events can lead to a surge in cases, and without travel restrictions, they can spread all over the country.
PM Jacinda Ardern said the level 1 move wouldn't happen unless case numbers continued to dwindle.
In the absence of any curveballs, confidence that the Auckland outbreak is contained will increase by Monday, when Cabinet meets to confirm the move.
But the chances of Covid-19 spreading outside Auckland may not have decreased.
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Those chances at the moment, according to statistical modeller Professor Shaun Hendy, are currently 20 to 30 per cent in the North Island outside Auckland, and 5 to 10 per cent in the South Island.
(The range is so wide because there remains a lot of uncertainty.)
The calculation is based on the probability of undetected spread in Auckland, and the chances of someone who doesn't know they have Covid-19 leaving the city.
The former will shrink in the absence of new, unconnected cases, but the latter will grow with the tens of thousands of extra flight seats out of Auckland. Everyone having to wear masks doesn't change that, though it limits the chance of spread on the plane.
And if the travel spike leads to Covid-19 being seeded outside the city, it may not be detected until after non-Aucklanders are already at level 1.
The nightmare scenario is this: A super-spreader person flies out of Auckland on Friday and attends an indoor function in Queenstown. They don't know they have Covid-19 and have no symptoms. They infect a dozen people at the function that in turn infect other visitors to Queenstown, who then take Covid-19 to different parts of the country.
No symptoms surface by Monday (incubation normally takes a week but can take up to two weeks), and Cabinet confirms the move to level 1 at midnight, at which time everyone around the country lets loose, giving the virus an additional springboard.
This scenario would be extremely bad luck, but it's not impossible. It's why public health experts - in the absence of an Auckland travel ban - question whether it's too early to go to level 1 freedoms next week.
That's despite the stellar work of contact-tracers who have managed to stay ahead of the case curve and quickly isolate contacts, including the 89 people who shared Les Mills classes last week with a quarantine nurse who didn't know she had Covid-19.
Effective contact-tracing can reduce the rate of spread by up to 60 per cent, but on its own it's not enough to contain a surge of cases at level 1.
That's because the average Covid-infected person infects between two and four other people. Keeping that to below one other person, Hendy's team says , would likely require further restrictions on top of contact-tracing and border controls.
Which was essentially supported by health chief Ashley Bloomfield this morning.
He told RNZ that his advice to Cabinet included a level 1-plus, with continued limits on gatherings and mask-wearing on public transport and flights.
"My view is there's merit in maintaining that as we drop down to alert level 1, and that's the advice I've given to Cabinet," Bloomfield said.
Ardern has said repeatedly that there is no room for politics in the alert level decisions.
Her political corner got lonelier yesterday after NZ First, National and Act all criticised Cabinet's decision.
She was at pains to point out that the decision followed Bloomfield's advice - but there was no mention of level 1-plus.
She may have been treading a fine line between managing expectations and softening any perceived fatigue of restrictions.
But she has now set a clear expectation of level 1 freedoms next week. That carries political risk of voter blow-back, not only if it doesn't transpire, but also if it does but then has to be walked back.