The government is facing heavy criticism for waiting until February to ditch hotel isolation, but Acting Deputy Prime Minister Grant Robertson is ruling out compensation.
A Ministry of Health document shows that Director of Public Health Dr Caroline McElnay and Director-General of Health Dr Ashley Bloomfield advised the government in November last year that the system was no longer justified.
However MIQ ultimately wasn't abandoned until almost four months later.
National's Covid-19 response spokesperson Chris Bishop said it was "outrageous" it took a complaint to the Ombudsman for the document to come to light.
"The idea that [the advice] was free and frank and that we shouldn't be seeing it is ... pretty bad," he told Morning Report.
At the time the government received the advice, there were lots of cases of Delta in the community but very few people with Covid-19 coming through the border, Bishop said.
"There was enormous pressure through the MIQ system and it looks like, in retrospect, we could have had a few more people through the system by moving to self-isolation earlier than we actually did," he said.
"I think, obviously there'll be enormous frustration from a lot of people out there who could've come home."
Robertson rules out compensation
A man who failed six times to get a spot in MIQ told RNZ he wanted compensation for those who could have skipped MIQ if the advice had been followed, as well as a meaningful apology.
Richard Lemare described the MIQ lottery system as "shocking" and said he was disappointed his complaints to MPs had largely gone unanswered.
"As they described it themselves, it was a lolly scramble ... there was a lack of compassion."
However, Robertson told Morning Report the government was not considering compensation for MIQ returnees since November.
He said he understood people were frustrated by the MIQ process but it was done for the greater good of all New Zealanders and had saved many lives.
Bishop said he sympathised with New Zealanders who were unable to return to the country while MIQ remained in place, saying the "human hardship" stories he'd heard over the past two years were difficult to deal with.
"There was this range of really bizarre circumstances where you had more people actually with Covid taking up the MIQ facilities from the New Zealand community, versus people who were New Zealand citizens offshore who were double-vaccinated, who didn't have Covid, and so of course those people - rightly - feel very frustrated by that."
However he wouldn't be drawn on the legality of keeping MIQ open after the government received the advice from McElnay and Bloomfield, saying a ruling in the court case taken by Grounded Kiwis was due soon.
"The justification for MIQ changed over time as the public health circumstances changed ... when it was put in place back in April/May 2020 it was clearly justified. The question of whether or not it was justified by November 2021 is an open question."
Omicron changed the playing field
Robertson defended the timeline for ending the MIQ system, saying the Ministry of Health memo was delivered to the government on 15 November and Dr Bloomfield wanted it peer reviewed, which was carried out by Dr Tony Blakely and Dr Philip Hill.
The review confirmed that MIQ was no longer needed but a careful transition would be necessary.
Dr Bloomfield knew that doing away with MIQ would be an irreversible decision so the Ministry of Health wanted the best advice, hence the need for a peer review.
Cabinet decided that MIQ would be removed in January but the Omicron arrival pushed the date out to February.
"Ultimately the advice was taken but a phased and careful approach was agreed to and then Omicron arrived and in many ways that reinforced the wisdom of that phased and careful approach," Robertson said.
"There is no doubt that MIQ has played an important role in keeping New Zealanders safe and making sure we limited the number of deaths...
"What we wanted to do was make sure that our transition away from it was a careful one and I think the right decision was made."
Epidemiologist professor Michael Baker told Morning Report MIQ had been "pivotal" to New Zealand's initial elimination strategy and rolling it back was always going to be a big change.
"It's great that the Ministry of Health was doing regularly-updated risk assessments."
The plan was to begin relaxing entry requirements from mid-January, Baker said, but "it changed with the emergence of the Omicron variant, as we know, in November".
He said the elimination strategy, which relied on "managing borders tightly" had saved over 10,000 lives in New Zealand.
"The government's approach has been quite cautious throughout and I think that's benefited New Zealand and it just takes account of the fact that pandemics are very unpredictable."