But his high and mighty commentary on RadioLive, combined with the implication on Twitter that a move was imminent, was bad.
Given his role in TV3 current affairs it was damaging to the channel which has been scoring big wins on Campbell Live.
TV3 head of news and current affairs Mark Jennings said he had no view on Garner's comments but he believed they were well-sourced.
"Duncan is a contractor for 3rd Degree, but I have no say what he does on RadioLive," he said.
Patrick Gower, who Garner said was about to announce details of the coup on Nightline on Wednesday, declined to comment. But he said he knew nothing about Garner's comments until he was called by the Labour Party at home.
Dirty washing
It's one thing to stick to your story as Garner did on RadioLive.
It's another to lose your cool to go on a slanging match with Labour MP Clayton Cosgrove.
Of course that is the sort of host they want on talk radio.
The question is how much that shock-jock attitude will reflect on shows like 3rd Degree.
Garner is a star-in-waiting at RadioLive - someone who can talk the station out of its deep ratings slough.
The move to take over the drive show in December has turned the former TV3 political editor into shock-jock.
Garner has an intimate knowledge of and contacts in Parliament.
On Wednesday, he allowed listeners and Twitter followers to be tangled up in his dirty laundry and housekeeping with contacts.
Garner did not return calls.
Golden oldie
I would like to say adieu to my days as a relevant consumer. With my 55th birthday this weekend I am departing the coveted mainstream - in the 25-54 demographic - to be included among those "55-plus".
It is true that some marketers have recognised the lack of logic in ignoring older consumers, but Chris Schultz of the senior agency, which caters for marketers trying to reach older consumers, says the bias is still alive and well.
Schultz blames mainstream ad agencies, saying they are loaded with young creative people who tend to push for younger audiences in advertising because that is what they understand. Media tends to follow the ad agency bias and of course that affects media content.
"Media are still entrenched in the core audience of people aged 25-54 and believe that with that demographic they will automatically get the 55-plus anyway. But that is not necessarily the case," he said.
According to Schultz the big difference reaching older demographics is to be direct and no-nonsense. "They do not want to hear the marketing fluff. They want to know what is in it for them and do not want to hear the big story."
"Get" Campbell
Campbell Live continues to dominate the journalistic high ground with TVNZ's Seven Sharp no longer competing for big stories.
In the past two weeks we have seen Campbell Live get the jump on competition with Bob Parker choosing to announce he would not stand again for the Christchurch mayoralty and the first to get Owen Glenn on screen to talk about problems with his troubled inquiry into abuse.
These are what is known as "gets" - stories that Campbell Live once competed for against TV One's Close Up. But with the 7pm show Seven Sharp focused on the light and fluffy, TVNZ appears to have walked away from the market.
TVNZ spokeswoman Georgie Hills said that TV One Sunday was still in that market. Seven Sharp appears to attract a stable audience but something is clearly missing.
You can argue how much serious journalism rates and whether Campbell Live's approach will be be sustained under new management.
Audiences should enjoy proper daily current affairs coverage while it lasts.
TV3 exposed
TV3 programmers have been thrown into a crisis trying to find a replacement for Home & Away at 5.30pm.
The show screens on TV2 on August 19 in the same slot.
But the Aussie soap is more of a huge loss for TV3 than it is a good win for TV2.
Four weeks is too much of a rush to come up with a permanent replacement.
It's been remarked often enough that it provides a lead-in to 3 News and Campbell Live. TV3 is looking for a short-term replacement to take it through until the end of the year. What sort of show would work?
Some fans of Paul Henry wish TV3 would dust off proposals for a Henry show at 5.30pm. But it would be a strange lead-in to 3 News, and nobody needs a show at 5.30pm that alienates as many people as it appeals to.
TV3's parent company at MediaWorks is in receivership.
In this case the receivership is a halfway house between the bad old days when it was drowning in debt, and a new enterprise owned by former creditors with renegotiated programme deals.
The loss of Home & Away illustrates the risk of this strategy and raises questions about whether that has been the best way for bankers to ensure the health of the enterprise which they now own. It also includes TV3, Four and half of New Zealand's commercial radio stations.
It is possible that everything will go according to plan and that the former banker creditors will be able to swap debt for equity and that during receivership it will be able to renegotiate programming rights.
However, it would seem that - as one financial source put it - the receivership option has left MediaWorks' flank exposed with the threat of losing more shows. It may be that receivers will be able to talk down the Hollywood studios. But if MediaWorks loses more content it might hurt future profits.
Tax dispute
KordaMentha believes that with receivership the $22 million contingent liability - relating to IRD claims - will not be carried over to the new firm.
The tax issue appears to have been put on the backburner after a decision to allow the precedent-setting Alesco case approval to go to the Supreme Court.
That could delay any discussion by IRD as to whether to seek redress for the $22 million.
Auckland University tax expert Mark Keating said a common outcome in such circumstances could be a partial payment against the threat of the IRD using its powers to place a firm in liquidation.
Prime Minister John Key made a surprising comment in Parliament recently when he suggested it was unlikely that taxpayers would recoup the money, because it was an unsecured debt. Key's comment was described by Labour revenue spokesman David Cunliffe as extraordinary because it sent a message to IRD officials that the government not expect them to recover debt.
