Key Points:

Truth will out, Shakespeare reckoned - but have you noticed how long it takes some curmudgeonly humans to accept it?

Last week, for example, we heard that new evidence dating the arrival here of the Pacific rat at 1280AD to 1300AD had not only settled, once and for all, the question of when Polynesians first arrived on these shores, but also finally laid to rest suggestions that New Zealand was first settled not by Maori but some other mythical people.

Actually, a mountain of evidence established this quite some time ago, but it seems not to have reached those people who remained wedded to an alternative reality.

Why do fanciful notions persist in defiance of the evidence? Professor Kerry Howe offers some answers in The Quest for Origins, in which he examines another question that has obsessed Westerners for 200 years: "Where did the Polynesians come from?"

Blame "an ancient conceit". Europeans couldn't believe that "allegedly primitive peoples" had beaten them to a part of the world that had eluded them for so long, so they constructed alternative theories that cast Polynesians variously as tanned Aryans, from Egypt, from the Americas, even as the lost tribe of Israel.

In fact, says Howe, the question was answered in the 1770s through observations of island peoples and languages made during Cook's voyages. It just took a little longer for everyone else to catch up.

So much for ancient Pacific migration.

The truth needs to come a little sooner for the people looking after today's Pacific migrants, the Immigration Service's Pacific division.

In a recent Herald article, the Labour Department's chief executive, Christopher Blake, tried to set the record straight on the unfairly maligned division, and in particular two staff caught in the media maelstrom that began with Immigration head Mary Anne Thompson's questionable conduct over her Kiribati relations' entry to New Zealand. Unfortunately, it came too late to undo the damage of weeks of unrelentingly negative coverage, some of it appallingly one-sided. Reporters weren't to be persuaded that a few missteps weren't evidence of a major scandal.

Even after Thompson resigned, the "scandal" widened to include the two high-flyers she'd hired to oversee the division's work: Mai Malaulau, the division's director, and her boss (and friend), Kerupi Tavita, who also heads Settlement and Refugees.

A barrage of stories based on unsubstantiated allegations and half-truths painted a picture of corruption, fraudulent dealings and ineptitude inside the division.

It was alleged that Thompson had given a $500,000 contract to establish the division to her "friend" Malaulau. (There was no such contract, and the two had only a professional relationship before working together.)

A conflict-of-interest allegation involving Malaulau and Tavita, already dismissed by an external reviewer, was rehashed, but without the context that led to the clearance.

And 19 cases of bribery, fraud and serious misconduct involving Pacific division staff were "exposed" as some dark departmental secret rather than a problem that Malaulau had already identified and tackled successfully. That's why the number of cases (the majority in overseas offices, a problem not confined to Pacific but China and India branches as well) fell from 10 in the first year, to six the next year, then three. There were none this year.

Public servants aren't always free to correct wrong and unfair reporting, even when their reputations are under attack. But their enforced silence leaves a vacuum that people with personal agendas are only too happy to fill. Thus, unconnected incidents were fused together and every immigration sin of the past 20 years laid at the door of the 3-year-old Pacific division.

I can't speak for Thompson or her qualifications, but I know both Tavita and Malaulau well. I'm not surprised Thompson hired them. I'd have done the same, not because I've come to know and like them, but because I know they're good. They're unusually well-qualified, well-educated, experienced and highly driven. There are very few people who can operate at their level in both Palagi and Pacific cultures.

We use immigration to smooth our foreign policy objectives in the Pacific, but it's long been a sore point for Pacific nations. The Pacific division is changing that. It's met unfilled Pacific quotas for the first time in years (and in record time), pushed through a seasonal employment scheme that's saving our horticultural and viticultural industries and earned praise from Pacific governments, Foreign Affairs and employers.

That it's now the focus of three costly inquiries is a scandal in itself. I've no doubt these will find that, at worst, mistakes have been made (unexceptional in a fledgling unit with a number of inexperienced staff) but no litany of lies, no corruption, no scandal. By then, the damage will have been done.