That's a pity for him because he has faced a public test of his character that few of his rivals have faced, and held up fairly well. Given the persistence of police culture, in the AFP as much as anywhere else, I am far from sure that all of his rivals would have done so well, at least as far as the public interest was concerned.

Kershaw is not the first person to discover that loyalty and duty are not simple matters, nor do they point only in the direction of unthinking obedience, especially in a highly disciplined and hierarchical organisation.

Kershaw, an AFP officer who had done the rounds of detachments to other Commonwealth criminal intelligence bodies, applied for an assistant commissioner's job in the Northern Territory Police in 2011. Like all small local forces, the NTP was highly factionalised along a number of lines, and governed to a substantial degree by the police unions, whose resistance to any commissioner's edict was usually fatal.

To make things more difficult in this highly incestuous environment, three of the members of the Country Liberal Party government, all ministers, were former officers, from lowish levels in the NT Police. All, naturally, thought themselves experts, mostly in the Peter Dutton sense, in all matters pertaining to policing, the justice system, and the appropriate penalties to be inflicted on malefactors if only the Northern Territory did not have namby pamby judges and magistrates.

There were two other assistant commissioners, one, Mark Payne, very much the favourite son of the police union. With the external jockeying as much as for internal peace and harmony, the then commissioner, John McRoberts, decided in his wisdom that the position of being acting commissioner when he was away would rotate among them.

One should not think that the Northern Territory is some sort of tiny backwater, similar to that subset of the AFP forcibly "rented" to the ACT "council" (as Peter Dutton put it this week).

Although the Northern Territory has only about 60 per cent of the population of the ACT, it has about 30 per cent more police in absolute terms. And to sustain an imprisonment rate four and a half times the national (and ACT) average, it also has an inordinate population of prison warders to ignore and defy governments of any stripe when anyone interferes with their right to treat prisoners, 84 per cent of whom are Aboriginal, as they wish. There are at least twice as many warders as in the ACT. The Northern Territory "justice industry" is about 2500 strong, which, excluding "national police" is about twice the numerical size, or, in per capita terms about three times that of the ACT.

The Northern Territory parliament, like the ACT Assembly, has 25 members, but these serve 25, rather than five electorates. A typical city electorate, where most of the cops and warders live, has about 5000 voters, of whom, in seats which have had a propensity to vote Country Liberal, there are on average about 200 cops and warders - about four per cent of an electorate. (After the last election, the CLP was more or less wiped out, but that is but a seasonal phenomenon, given the Northern Territory's budget problems.)

One can see that when the CLP is in power (as it was when the serpent entered this garden of Eden) ordinary cops had inordinate political influence and representation.

Darwin may exceed Canberra for political incestuousness and cronyism. Nearly everyone of any clout knows every other person exercising power of any sort, whether in politics, government, business or the sexual, sporting and social whirl. This combines with the simultaneous wearing of different hats, sometimes as members of government boards or charities, sometimes as rapacious developers or urgers, as well as being "mates" who fish together, go to the footie together or tip each other off about business opportunities. It is not always clear which hat any person is wearing at any one time.

The Northern Territory's openness to home-grown corruption is accentuated by the fact that the territory is always awash with Commonwealth money (received at a rate of five times a head greater than the benighted subjects of the ACT "council"). Even now, with the strain showing, there is more fraud, waste and mismanagement than in the Commonwealth's marginal electorates infrastructure schemes. In the Northern Territory, the principal and bipartisan industry of the white population is turning to its own use the overwhelming proportion of Commonwealth taxpayer money intended to go to Aboriginal development and welfare.

Naturally cautious local politicians have decided that the anti-corruption framework it has now decided is necessary will hold no public hearings and issue no public reports, lest any innocent person be smeared.

The testing of Kershaw began in 2012. Fraud detectives decided to look at the activities of 27 local travel agencies with Northern Territory government contracts of one sort or another, in the face of rumours that almost all of them were rorting, with false or padded claims. They focused, at first, on a well-known Darwin socialite with lucrative government travel contracts, including transportation of sick Aborigines in remote communities. In the Canberra manner she was a friend of most of the politicians, especially the CLP ones, and bureaucrats, was at all of the parties, functions and sporting events, and a member of industry boards lobbying government, government boards sharing out goodies to each other and of prominent charities.

Although this was not initially known, she was also the mistress of the police commissioner, and had, apparently, earlier been the mistress of another. It must have been the uniforms.

Apart from general rorting on a large scale, she had also bribed the chief of staff of one CLP minister with kickbacks on travel jobs he diverted her way.

By 2014, McRoberts was briefed on the investigation, already several years old, and suddenly seems to have become alarmed that a raid on his mistress would reveal his affair. Although he said he "knew her," he did not disclose his conflict of interest. But he began taking an inordinate interest in the case, disparaging the adequacy of evidence gathered, and asserting that the brief was not at the stage where search warrants were justified. His efforts had the effect of deflecting and frustrating the investigation, at least as a criminal prosecution.

Then he came up with the notion it would be better to send "fraud civil debt" notices to travel agents, inviting them to 'fess up and voluntarily pay back any overcharged money. This would, he thought, be better than criminal proceedings and not threaten the tourist industry.

There was no suggestion McRoberts tipped her off. His only motive, it was said, was to conceal his affair. Behind the scenes were detectives becoming deeply suspicious of his interference. Kershaw found himself the conduit of instructions from the commissioner blocking the execution of a search warrant, pending the answering of questions being asked by McRoberts.

During the trial, a senior detective was asked why he did not question the direction from Kershaw to stop the warrant. "If the assistant commissioner rings you up and tells you to do something, you do it," the detective responded.

But McRoberts lost his control when he left on a trip, and assistant commissioner Payne was in charge. Answers to the questions having been supplied, he authorised the raid on the socialite, and in front of TV cameras too. McRoberts was furious, but still trying to protect himself, telling Adam Giles, the chief minister, that the raid had been "a very poor decision," indicating that he blamed Payne, who soon after, was exiled to bureaucratic Siberia.

Whether or not as a measure of that displeasure against Payne, Kershaw found himself with a better portfolio of day-to-day responsibility, and became the everyday deputy.

The raids produced thousands of emails and texts revealing the intimate association with the commissioner. Payne briefed Kershaw and together they told McRoberts, who continued to deny it.

Kershaw found himself, willy nilly, in the tricky business of authorising and supervising an investigation, knowing that his own boss was implicated. He seems to have juggled it without ever disobeying an order.

There are not many textbooks on the subject. Nor is it always clear what the right thing to do is, given issues about command prerogatives, and some consciousness that the problem had a political as well as a rule-of-law dimension. His evidence at trial suggested that he had managed the conflict well, if, so far as we are aware, without taking the problem to anyone outside the force. That did not prevent defence counsel from asking whether his self-interest had affected his independence and ethical behaviour, given that he became Commissioner when it all went into the public domain.

The investigation continued without further interference. But a widening number of detectives came to know of McRoberts' affair and his pattern of intervention. We do not know how the case would have proceeded in the ordinary manner, because, suddenly, two months after Kershaw and Payne had told McRoberts that he was blown, a whistle-blower, whose identity is still not known, forced everyone's hand. They tipped off the police minister, Peter Chandler, an ambitious deputy to Adam Giles.

Given Giles' perceived closeness to McRoberts, this was material that could feed into the political assassination of Giles. By Northern Territory tradition, as for example when Giles overthrew the previous chief minister, coups begin when the chief minister is out of the jurisdiction and are intended to be a fait accompli by the time he returns.

Giles, tipped off, rushed back to Darwin, to discover that McRoberts had been pushed out and two former policemen had announced themselves in the parliament to be the new chief and deputy ministers.

To Giles, it seemed that the deposition of McRoberts was a part of the plot, given that McRoberts had blamed Payne for the raids, and that the coup plotters had earlier pushed for Payne to be made deputy. He suggested police were somehow involved in a conspiracy against him. A nagging issue for him, still unresolved, was the timing of the whistle-blower's disclosure, two months after the facts were known by detectives. It seemed planned for when he was in the air, out of touch.

Kershaw became acting, then confirmed commissioner. There were several external investigations into the McRoberts' aspects of the affair, and, ultimately a trial for attempting to pervert the course of justice. That brought out a good deal of material, but the reports are still secret, and there is a good deal more to be told. It seems doubtful, however, that it will reflect adversely on Kershaw or Payne.

Kershaw's Northern Territory experiences will also have reminded him that a police force seethes with politics, with gossip and endless speculation about the actions and motivations of superiors, and, for some, ready access to politicians, journalists and others capable of making mischief and trouble, usually anonymously, even beyond the capacity of electronic surveillance, bugging and metadata systems. The NT experience suggests that such problems are better dealt with by honesty and integrity, and transparency, than by creating a reign of terror or staring down the critics.

One suspects that his experience will inspire a good deal of caution about allowing himself, or the AFP, to get too immersed in politics, or of being seen as some sort of bureaucratic tool of the government, in no different position than any government agency.

One might also expect some resistance to the idea that the AFP, as an agency in the home affairs portfolio, is at the bidding of Mike Pezzullo and his efforts to carve for himself the premier place in the terrorism, law enforcement and counter-intelligence domain. Kershaw, like Andrew Colvin, is right across the national politics of criminal intelligence, counter terrorism, cyber-crime as well the mechanics of human resource management. If he does not assert his independence early, his effective subservience to other agendas will be assumed.

Last week I was in error in saying that the AFP College in Barton - the former Barton House - was the site of the Pine Lodge bar, illegal casino and brothel. That was Lawley House, also in Brisbane Avenue. My only explanation - it is not an excuse - is that I have always been a north-sider - with my south-side compass based, in those days, on the (old) Parliament House, the "Wello'' and the restaurants of Kingston.

One of my spiritual advisers - the first to draw my attention to this egregious error - has suggested that I "now have no alternative but to make a grovelling apology and perhaps tender your resignation.''