Perhaps, in the case of a department whose decisions often seem to be utterly random, the 'legal reasons' are simply a reluctance to be exposed as immune to facts or the merest whiff of empathy. Immigration seems to want us to believe that it possesses information that we don't have. More likely it won't share that information with us because it doesn't exist. And that doesn't seem to change even when one minister makes way for another.
Ms Williams is cut from the same cloth as her predecessor, Kris Faafoi. He steadfastly refused Mr King's pleas, backed by enormous public support, to intervene on behalf of Kaitaia couple Juliet and Eric Garcia, whose case for permission to apply for resident visas was utterly compelling to everyone except him, including Mrs Garcia's employer, who repeatedly made it clear that she was effectively indispensable.
The couple had done everything asked of them, but it was only as Mr Faafoi literally prepared to hand over his portfolio that he condescendingly agreed to make an "exception" for them. How very kind of him. Having studiously ignored what should have been an irresistible case, he finally did the right thing as some sort of personal favour.
It is little wonder that politicians in this country are held in such low regard.
And now Poto Williams is following the same recipe, and refusing to say why she has decided not to intervene on behalf of the Jias. Many questions need to be asked, and are deserving of answers. Such as, why were the couple declined asylum in 2016, given their claims of religious persecution? What 'legal reasons' could possibly prevent the minister or her staff sharing that with us, assuming of course that the Jias have no objection? Whose privacy is being protected here, theirs or the associate minister and her department's?
Why has Poto Williams declined to intervene? Why has she ignored the huge level of public support that has been shown for the Jias? Why is she so keen to expel a family whose adult son has been granted a resident visa, and have proved themselves to be much worthier candidates for residency than some who are granted it?
What does she know that we don't? And what statute exactly makes it inappropriate for her to explain her decision?
The privacy laws in this country are increasingly used by officials, from Cabinet ministers down, as a means of avoiding any kind of public scrutiny, and this is just another example of a stance that, to use the technical expression, is utter crap.
This newspaper comes up against it on a regular basis, most memorably some years ago when a child, aged two or three, if memory serves, was badly served at Whangārei Hospital. She was shunted from pillar to post until she was finally diagnosed with a twisted bowel, an extremely painful condition that might well have killed her. Her mother came to this newspaper in one last attempt to obtain some sort of explanation.
The Northland DHB wanted to co-operate, of course, but could not do so unless the patient waived her right to privacy. The child's mother did that on her behalf, but that wasn't good enough. The waiver had to be provided by the child, who at her age was obviously unable to do so. The questions her mother sought answers were therefore not forthcoming.
Poto Williams, like her predecessors, has the same modus operandi. Unless she can provide incontrovertible evidence that it is in the Jias' best interests not to do so, there is absolutely no reason why she can't tell us why she has refused to intervene, and why this family are considered to be unworthy of resident visas.
The inescapable conclusion is that it would be inappropriate for her to comment on this individual case because she cannot do so without exposing herself as unfit for her office. The same applies to her officials.
What possible legal reasons could there be for them to refuse to explain the process that has taken place? If such reasons do in fact exist, please disabuse us.
Granted, Immigration no doubt receives applications for residency based on humanitarian grounds on a daily basis, and some difficult decisions have to be made. However, in this case, and probably many others, there is strong public interest in the outcome. All anyone is asking for, at this stage, is an explanation of the process that has led to this decision. All we want to know is why this family aren't welcome here. Is that too much to ask?
Obviously it is as far as Poto Williams and her department are concerned. They expect us to accept that they know best, and we don't need to know any more. So much for transparency. So much for fairness. So much for common decency.
So who cares if this family, who say they are desperate to stay here because of persecution they have suffered, and who are in no doubt that they will be persecuted again if they return to China, are kicked out? Quite a lot of people actually, people who, unlike Poto Williams, know them, know what they are doing for their community, and what they will continue to do it if they are allowed to stay.
That support clearly means nothing. Immigration sees no obligation whatsoever to explain how it works. This department, from the minister down, is a bloody disgrace.