Deputy Prime Minister Grant Robertson says no public health advice is perfect, after newly released documents show officials thought the Delta outbreak was under control.
Health advice given to ministers on 20 September show Director-General of Health Dr Ashley Bloomfield was confident the outbreak had been contained in Auckland.
"It appears to have peaked on 28 August with daily numbers generally decreasing or remaining static at low levels as the expected tail of the outbreak manifests.
"Where there have been small daily increases, these have been linked back to existing cases (e.g. household contacts) or around the scheduled testing requirements."
The advice said the risk in Auckland was deemed to be medium.
By 30 September there was a change of tone in advice to ministers.
"As of 29 September 2021, the seven-day rolling average of Covid-19 cases in the community is 18, and this number has not changed since the previous Public Health Risk Assessment on 18 September 2021.
"There has been a persistent tail of cases in Auckland with continuing spikes."
However, the risk was still deemed as medium for Auckland and low for the rest of the country.
By mid-October the government had shifted away from elimination.
Today, Robertson said overall the Delta outbreak had been dealt with well.
"The ministry has provided us with good and strong advice. Does that mean it's 100 percent perfect? No, it doesn't, but that's why we try and learn from the [Brian] Roche report and the experience we have," he said.