Michael Baker is an epidemiologist from Otago University and joins Lisa Owen with his analysis.
"I think this is the right decision," Professor Michael Baker told Checkpoint.
"The evidence was coming in that this was not a widespread community outbreak. There's a plausible link for this family to the airport and to incoming travellers.
"So that's how it was very different from the August outbreak we saw in Auckland last year."
But Professor Baker said he would like to see tweaks in the alert level system as more is learned about Covid-19.
"We've been arguing for a long time that the alert level system was great when it was introduced last year, but it needs to move on and keep ahead of the virus.
"We know a lot more about how the virus is transmitted now, it's mainly indoors in poorly ventilated environments where there's crowding, it's in droplets and aerosols.
"With that knowledge we think there should be a lot more emphasis on the use of masks and focusing on those high-risk indoor environments.
"The main aim of this is to get tough on the virus and have minimal restrictions on people. That means just revising this alert level system maybe to have a 2.5 and a 1.5, so we can be more nuanced, and more geographically targeted.
"That's the way we're using the system now, it's more surgical in its approach. And that's better because it minimises disruption for people."
New Zealand's Covid-19 contact tracing has been very good, and incursions of the virus have been well-managed, Professor Baker said.
"We're still waiting for some test results from those other students and if that showed there was more transmission than expected, that would obviously be a problem.
"But I think the bigger concern really is if we see cases in the community that we can't explain."
