The prison staff union leader says it's ludicrous to call six days of fiery destruction at Waikeria a "protest".
And prison authorities say the Waikato jail has insurance but it's not yet known how much the damage will cost taxpayers.
Corrections Association president Alan Whitley said prison workers, police negotiators and firefighters endured six days of hard slog as the riot caught the gaze of politicians, commentators and the wider nation.
Most of the Waikato Corrections precinct's high-security section known as the "top jail" has been destroyed.
"As a layperson looking at it, I can't see how they'll reinstate that for use," Whitley said.
Herald photos show wrecked roofs and scorched walls in the high-security complex (HSC), which sits within perimeter walls in part of the 1200ha site.
"Fires were set almost on a daily basis. The prisoners had access to the entire jail where they were able to move through and they were setting fires," Whitley said.
Lance Burdett, a former police crisis negotiator, said the Waikeria riot's duration was of serious concern.
"The longer it went on, the worse it got."
Burdett said an independent review was needed to assess if tactics used in the stand-off were appropriate.
Food was withheld from rioting inmates and Burdett said he hoped details about tactical manoeuvres at Waikeria would emerge in reviews.
He said applying a harsh or inhumane approach to prisoners who were rebelling due to harsh or inhumane conditions was pointless.
Burdett said in the 2009 Napier siege, some police suggested gunman and murderer Jan Molenaar be kept awake throughout the night.
"I said no, let's not keep him awake, let's let him sleep. When people get tired, they don't think rationally."
The Corrections Inspectorate, its Chief Custodial Officer, and police are already investigating but Amnesty International also called for an independent Waikeria review.
Burdett said somebody with no vested interests and the ability to objectively analyse information, such as a lawyer, should head the review.
Whitley said the Corrections Association had no problem with an independent inquiry.
"There's nothing to be feared from a totally independent and external review."
Whitley said on the riot's final night, an attempt to take control of the top jail contained the prisoners but did not end the stand-off.
The riot aftermath was now reverberating across the Corrections system.
Whitley said 246 prisoners in the top jail, about a third of all Waikeria inmates, had to be redistributed across the national prison network.
He said some facilities elsewhere that were to be phased out now had to be brought online promptly to house inmates moved from Waikeria.
Whitley said Corrections Minister Kelvin Davis should have voiced support for and trust in Corrections staff earlier.
He said no Corrections staff expected Davis to interfere in daily operations but Davis should've publicly acknowledged staff before the stand-off ended.
Davis on Sunday had he didn't speak publicly sooner, partly as doing so would have emboldened rioters and supplied them with political attention they craved.
The prison chaos commanded political attention anyway - from the National Party and from Māori Party MP Rawiri Waititi.
The National Party lambasted Davis for keeping a low profile.
On New Year's Eve, Waititi journeyed 360km journey from Cape Runaway to the prison to hear inmate concerns and defuse tensions.
Whitley said jail staff were dumbfounded when inmates were delivered takeaways as Waititi arrived at the site.
Whitley acknowledged Waititi's help in bringing the stand-off to a peaceful end but added: "The staff had to stand there while the prisoners got fish 'n chips and coke."
He said Waititi honoured a pledge to accompany prisoners to safety but Corrections staff would have ensured surrendered prisoners' safety anyway.
Waititi said the goal was to ensure the 16 men came down from the roof safely.
"We needed to negotiate for a positive outcome and whilst food and drink was a small part of those negotiations, it was critical."
Waititi said negotiations were fruitful and he knew the surrender was imminent, so he returned to Waikeria on Sunday.
"The kai was the final part of our lifting of the tapu on the 16 whānau," he added.
Waititi said he also thanked Corrections staff for their hard work.
"I did this kanohi ki te kanohi (face-to-face), not over social media."
Waititi said the country must examine transitions from a criminal justice system to a better way delivered by Māori, for Māori.
"We need to implement positive and transformative kaupapa that uplifts our whānau and works to strengthen their mana to become better people."
"Right now, however, the Minister and associates need to be able to assure us that the prisoners will receive clean water, clean bedding and clothing as a basic human right."
Whitley said commentators who called the unrest a protest had left Corrections staff aghast.
"They're disgusted by it, to be perfectly honest. They were put at risk. The risk continued for the full six days."
He said unruly inmates repeatedly escalated tensions.
"They were being violent towards anybody who was getting near them."
"It wasn't a protest. It was a riot."
Fires lit during the chaos caused some health concerns.
A Department of Corrections spokesman said St John were present throughout the event, offering medical support to everybody involved.
He said staff involved were monitored for injury and smoke inhalation.
"No-one has reported any ill effects since the event but have been advised that if their situation changes they should immediately see their GP."
He said the 16 prisoners who rioted until Sunday were given water, food, and dry clothes on surrendering.
Corrections said the inmates had access to medical staff and the ability to speak with kaumātua.
The department said it had insurance to cover events such as last week's riots.
The top jail was still a crime scene on Wednesday, and Police and Fire and Emergency NZ had to complete investigations before the cost of damage could be counted.
The department would not comment on tactical options used in the stand-off.
The Herald heard from one rioting inmate's partner.
She said he apologised to her and he expected to face more jail time for the disorder.
She said he was stuck in an escalating crisis, and depressed due to inhumane treatment and filthy conditions while serving time on remand at the HSC.
During the unrest, abolitionist group People Against Prisons Aotearoa uploaded a manifesto in which it said inmates highlighted dreadful conditions.
The document claimed prisoners were deprived of clean clothing and suffered indignities including having to eat from paper bags next to open, shared toilets.
Davis disputed such claims, saying many rioters were Mongol and Comanchero gang members, and some were deportees from Australia.
In a report last August, the Ombudsman cited serious concerns with Waikeria's high-security complex.
The report found most men in the HSC were double-bunked in cells meant for one person, living conditions were poor, and violence was rampant.
Amnesty International suggested the unrest should catalyse a broader review of prisons.
"Our prisons are a signifier of the health of our society," Amnesty's executive director Meg de Ronde said.
"People expect all people, including those living and working in a prison, to be treated with dignity. That is not what we see in our prisons today."