When you introduce a high-trust model of working into a sector known for unscrupulous behaviour, the results aren't pretty.
It was an answer to a problem that didn't exist.
And it was a mess.
When the Labour government introduced the Accredited Employer Work Visa in 2022, it was a reaction to some horrific stories of migrant exploitation, mainly of recently graduated students trying to make a living.
It rolled six older visas into one and was designed to go from a system that relied on migrants themselves to present all the relevant data to authorities in an application, to one that focused on employers to make genuine offers of work.
The policy change took place between 2017 and 2019, and then work on implementing it was done while our borders were closed during the pandemic.
After they reopened the pressure was on - it was a time of unprecedented labour shortages, very low unemployment and a pent-up demand for migrant labour, not to mention the influx of friends, relatives and wedding guests who'd put off their trips because of Covid.
New immigration staff were being trained up; big changes had been made; there was immense pressure from the government, employers and New Zealanders generally to get people in the country quickly; and INZ was part way through introducing a new computer system that split tasks up and ensured one person didn't have oversight of cases. The system was called ADEPT; it was so bad that some immigration advisers referred to it as INEPT.
On top of all that INZ adopted a 'light touch' policy - staff were told to initially cut back on the checks designed to stop bad actors exploiting the system. More rigorous checks would come in later. But that didn't happen.
Once that became known, the floodgates opened.
Staff, the immigration industry and lawyers raised concerns about the new processes, including the lack of checks. One of the first to ring alarm bells was immigration lawyer Alastair McClymont. His business partner was encountering job tokens for New Zealand positions being sold openly in India, Vietnam, China and elsewhere for tens of thousands of dollars.
"Certainly it became obvious to many people in the industry that there was a lot of money exchanging hands overseas," says McClymont.
"When something's going wrong like this and you start to hear stories about the amounts of money being paid ... the stories build up and you hear more and more and more of them ... and then you can connect those to what's happening on the policy front, and what's happened with Immigration New Zealand .... it's very easy to see those direct connections.
"It was the policy design that opened the door to it being abused.
"The people who are out there to make money, and to do the exploiting ... they are the most adept at identifying opportunities. They're always the first people off the block."
But McClymont says the new policy wasn't even needed in the first place - the problem that had previously been provoking exploitation had been solved with changes to the student visa.
"That wasn't the visa space where the problem was," he says. "It was a perfect storm of total incompetence to be honest."
The review of the new visa says that in 2011/12, INZ received exploitation allegations involving 31 individuals and businesses. In 2018/19 this had increased to 390, indicating an increase in the level of exploitation.
The number of allegations involving at least one employer has been climbing, with 421 in 2020, 590 in 2021, 467 in 2022, and as of December last year, 1552 complaints against Accredited Employers where one or more migrants reported instances of exploitation.
McClymont says some of these problems are still going on, but because the processing of applications is so much slower now, they are getting a more thorough looking-over.
"But the main players in the industry who were out to make money out of people have made their money - and have taken it and got out of it quickly. There are lots of rumours going around of people who have banked half a million dollars, in a very short period of time."
RNZ's immigration reporter Gill Bonnett has analysed the review and talks to The Detail today about its findings.
She runs through the specifics of where the chinks in the system were, and how those issues surfaced in the first place.
Check out how to listen to and follow The Detail here.
You can also stay up-to-date by liking us on Facebook or following us on Twitter.