Justice advocates say Waikeria Prison should have been mothballed long ago and only systemic change can improve conditions for Māori.
The remaining 16 inmates protesting over dilapidated conditions and Corrections' failure to implement its strategy for Māori, surrendered to the authorities on Sunday after six tense days.
Corrections has launched two reviews into what happened.
Lawyer and criminal justice reformer Julia Whaipooti said it was inevitable prisoners would retaliate, because the system was failing them and in some cases sending them back out into the community worse off.
She said Corrections needed to change how it operated and where it puts resources - to not only benefit inmates, but also those who work behind the wire.
"You cannot work inside an archaic, concrete institution where we treat people, family members who end up inside prisons, as animals - it is something that we should find unacceptable in this country," she said.
The inmates have told RNZ they are protesting dilapidated conditions, cramped cells, a lack of basic supplies and Corrections' failure to implement its own strategy for Māori.
That strategy, Hōkai Rangi, is meant to reduce the over-representation of Māori in New Zealand prisons.
Whaipooti said Corrections needed to give prisoners their basic human rights.
"But if we don't address what sits behind how they harm, why they're harmed, then we're actually not dealing with the causes of offending and we're sending people back out worse off who will cause more harm.
"So it's really looking at people, seeing them as people, and rehabilitation."
Local iwi Ngāti Maniapoto said it was clear the criminal justice system was not working for Māori.
Maniapoto Māori Trust Board chair Keith Ikin said Hōkai Rangi was the best tool on the table to facilitate meaningful change.
"I would suggest that we look to put our weight behind Hōkai Rangi and ensure that there is appropriate review along the way and we adapt and change direction if we need to," he said.
Waikeria Prison opened 110 years ago and houses inmates with security classifications ranging from minimum to high.
In August last year, the Office of the Ombudsman published a report following an unannounced inspection of the prison.
It found while the low security areas were well-maintained, the high security areas were not fit for purpose and this was seriously affecting prisoners' treatment.
Furthermore, the report highlighted problems with lax reporting on use of force by prison officers.
Thirty-eight reviews of such incidents were outstanding at the time of inspection, some dating back to April 2019.
Inspectors reviewed 11 incidents, including viewing CCTV and on-body camera footage, but found these were not always switched on prior to force being used.
Justice advocate Kim Workman used to be head of prisons 30 years ago.
He said the facility - which is slated for replacement in a couple of years - should have been vacated by now.
"The Minister [of Corrections] would have to agree to it - and I don't see any benefit in holding people in what are sub-human conditions if that's what any inquiry finds," he said.
Just Speak director Tania Mead said the situation at Waikeria showed it was time to rethink the practice of simply locking people up, especially remand prisoners.
"That would help address the causes of their offending and why they're in the justice system in the first place - it's a deeply ineffective solution - and yet we've continued to fuel that response and what we see as the result of that is significant and growing numbers of people held in prisons for long periods of time who have not been sentenced to prison," she said.
Chief Ombudsman Peter Boshier said his investigation in August found the high security unit at Waikeria was old and no longer fit for purpose.
"In short, the conditions are decrepit and baring on the inhumane and by that I mean it's the oldness and the not-fit-for-purpose nature of it, that means we've commented now on this report on the unacceptable nature of it.
"When things stop working and you've got conditions don't provide the stimulation and the hygiene that you'd expect of modern day facilities, it's time for them to go."
Boshier said his investigation did not find the quality of the drinking water to be as bad as the prisoners had described it, nor did he receive any complaints about it.
He said now that the stand-off has ended he wanted to be briefed by Corrections before deciding whether he would undertake his own investigation.
Corrections chief executive acknowledges facility was inadequate
Corrections chief executive Jeremy Lightfoot told Morning Report that he acknowledged the high security arm of Waikeria Prison was no longer fit for purpose.
He said the Ombudsman's report highlighted problems Corrections needed to address and it had been working through them.
"That is why we are building a new facility to replace that top jail on site, that will be completed in 2022, but we haven't sat on our hands, we have acknowledged that in that two-year period there are some things we can do to improve the amenity, and that has included an ongoing programme of maintenance.
"And actually after the Ombudsman's inspection, which was published 10 months after and took place in October 2019, we have made significant progress which was recognised in a follow up inspectorate visit to the site in January 2020."
He said the area the prisoners set fire was now a crime scene and Corrections had to wait until police are done with their investigation before they could try to retrieve any property of the prisoners who were housed there.
However, he said he was not expecting to retrieve much.
Lightfoot said two internal reviews into the riot would be undertaken.
The first will be an operational review undertaken by Corrections' chief custodial officer that was intended to provide quick insights around any operational matters Corrections could apply across its network as a result of the incident.
The second review will be run by the office of the inspectorate - an independent arm of Corrections that answers to the chief executive.
Lightfoot said he told the chief inspector he would like to see the implications in the lead up, what some of the causal factors were, how the incident unfolded and risks associated with that, and any other systemic issues that Corrections might benefit from understanding.
Corrections has been criticised by the Ombudsman in the past for failing to accurately report on incidents at its prisons.
Despite this, Lightfoot said the public and prisoners could have faith in the organisation's reviews.
"This is not being carried out by Corrections internally, this is being undertaken by the separate office of the Chief Inspector, her function, by purpose, is very separate and I think if you look at her investigations and reviews, you will certainly see the independent nature of her work."
Lightfoot said the Chief Inspector had completed a first draft of the terms of reference for the review in the past couple of days and he had agreed to it.
On the prisoners, Lightfoot said the 16 protesters were medically assessed the day they surrendered and have been moved to various prisons.
He said another 200 inmates in the cell block that was gutted by fire have also been moved to other prisons, and work was being done to address the trauma the protest caused them.
On top of that, Corrections said it was trying to reconnect the 500 prisoners remaining at Waikeria with their families after the fire brought down telephone capabilities at the facility.
Meanwhile, the president of the union for prison staff says employees deserve recognition for quick thinking when fires were set inside the prison.
President of the Corrections Association Alan Whitley said guards moved inmates away when fires were first started in an exercise yard a week ago.
He praised staff for handling what he calls an 'all out riot', not a protest.
Whitley said staff worked in horrendous conditions, as fires were lit around them and they had to move others out of harm's way.
MPs call for independent review
Green MP Golriz Ghahraman supported the idea of an independent review into what happened at Waikeria Prison, outside of the two reviews Corrections was undertaking.
"We've found with the Ombudsman's really damning report that came about as a result of a surprise visit that we're really not even meeting sanitary standards and that's exactly what the protesting prisoners in the latest crisis were highlighting, things like that, so we've really fallen short," she said.
"The key thing for us is that there's transparency and independence in whatever review comes, but also that it comes hand in hand with an acknowledgment that actually imprisonment seems to have failed to do what we want it to do, which is to keep communities safe and bring down rates of crime."
National Party spokesperson for Corrections Simeon Brown backed calls for an independent review.
"I think we need to have a full independent investigation into why it [the protest] took place, how it took so long and why it took so long to resolve.
"These are all important questions because what we've seen is the entire prison completely destroyed by 16 violent rioters."