My regulator inquisitors were not impressed that I had refused to reveal my sources. Their threat didn't change my answer and wouldn't to this day.

So, as a journalist who's been threatened with legal action, when it comes to a question of whether someone should break the law because of a matter of principle, I have some sympathy for the view put forward by new ACTU chief Sally McManus that has attracted criticism from some quarters.

What is concerning though about McManus' controversial ABC interview last week was the misleading way she depicted the Construction, Forestry, Mining and Energy Union's (CFMEU) totemic battle with construction company Grocon to make her point.

In her interview with Leigh Sales on the 7.30 Report, McManus said: "Grocon got fined $330,000 for killing five workers, where the CFMEU got fined even more. And I just think that's totally wrong."

The problem, as McManus herself has subsequently admitted, is that Grocon has not killed five workers.

It simply has not, and incidents like this should be above loose point-scoring.

Here are the facts. Three innocent, young pedestrians were killed in March 2013 when a brick wall at a Grocon site blew over on top of them near Melbourne University.

It was a shocking incident. Among first on the scene were heroic CFMEU officials who removed bloodied bricks with their bare hands.

Grocon, through a subsidiary, eventually pleaded guilty to failing to ensure a safe workplace and was fined $250,000 (not $330,000). A sign company who had a role in hoardings on the wall was fined a further $250,000 after fighting the charge.

McManus is right, in my view, to regard those fines as woefully inadequate.

A second death occurred a few weeks earlier when a Grocon worker fell from a crane. This was not a workplace incident, that has been made clear by the coroner and is well known within the industry.

The fifth worker mentioned by McManus? There isn't one.

Grocon issued a furious retraction demand late on Friday claiming that it had never been held responsible for anyone's death. Given its subsidiary's guilty plea over the wall, this is an over-reach and a callous exercise in legal hair-splitting.

But McManus has twisted these facts to suit her agenda.

Asked to clarify her position, she now admits she wrongly claimed "five workers were killed" yet continues to argue that Grocon had a role in the crane death.

This is a deeply concerning approach to basic facts about serious workplace accidents, especially in the face of compelling evidence.

Instead of backing down, McManus also said it was still "accurate to point out that the huge discrepancy in fines paid by the company and the CFMEU is a glaring example of the inherent unfairness in our industrial relations laws".

Which brings us to her suggestion the CFMEU has been unfairly forced to pay millions of dollars in fines because its unlawful strikes, at Grocon and elsewhere, were linked to workplace deaths.

"Quite often these workers have stopped work because a worker has been killed on a building site," she told the ABC, before her poorly informed foray into the Grocon case.

The facts don't bear out her claim. Crucially, in the Grocon case, most of the conduct for which the CFMEU has been fined happened in 2012, well before the horrific wall accident or the crane death.

Not only that, the biggest payouts had next to nothing to do with Grocon. The steepest imposts came from a ruthless black ban of concrete company Boral for supplying Grocon. Boral found out it was black banned after its customers cancelled orders citing pressure from the union.

Boral had nothing to do with any of the deaths and also lodged its court action against the CFMEU before the tragic wall incident.

The CFMEU weren't walking off a site after a death; they were engaged in a bitter industrial dispute with Grocon over the appointment of safety officers and conducted a secondary boycott in order to try to win it.

In 2015 the union agreed to pay Boral up to $9 million to settle the court case without admitting any of the allegations. That dwarfed the $1.15 million the union had to pay for contempt of court stemming from its high-profile blockades of Grocon sites and well above the $3.5 million it had to pay Grocon in damages (again it denied liability).

That alleged boycott though is still the subject of criminal blackmail proceedings against two of the union's most senior members, Victorian state secretary John Setka and his deputy Shaun Reardon.

When McManus was asked by Sales to reflect on the conduct of the CFMEU, including whether she would back away from the union, she replied, "there's no way we will be doing that".

She then added: "I'll tell you this: the CFMEU, when they have been fined, they have been fined for taking industrial action."

Asked the same question last year, former ACTU leader and Labor prime minister Bob Hawke told The Australian that the ACTU would be better off without the CFMEU in the fold.

Another former ACTU president and Labor leader Simon Crean has repeatedly called for the CFMEU to be reined in.

Neither would comment this week when contacted by my colleague Anna Patty.

Why do Hawke and Crean feel this way? Because the approach of the CFMEU is out of whack with what even most unionists would consider reasonable industrial defiance.

Statistics from the ABCC give a good insight into what it looks like on a day-to-day basis. The CFMEU are respondents in 56 current prosecutions with 110 of their representatives facing 1076 alleged contraventions.

Of those 56 cases, 19 surround right of entry. This is one of the most common prosecutions where CFMEU officials disregard laws around right of entry to building sites, which is tightly controlled for safety reasons.

In order to obtain a right-of-entry permit an individual must pass a "fit and proper person" test, which many CFMEU top brass don't pass.

Not that it stops them barging onto sites. Court judgments recount on-site conversations and cast a poor light on those involved. Site managers asking for legal process to be followed are routinely abused and bullied.

In one celebrated case in Adelaide, an ABCC inspector was subjected to this tirade at close quarters: "You're just about having a heart attack. You're shitting yellow, you piece of shit. Go f------ brush your teeth next time, you piece of shit, all right? You f------ coward, I'd f------ take you to school, you f------ piece of shit."

This is the sort of behaviour being compared with the dignified resistance of Gandhi and Rosa Parks on social media.

You see, I would contend that how you go about breaking a law plays into the ethical calculus. McManus suggests the rampant bully-boy style of the CFMEU is a valid industrial tactic.

Yet at the same time McManus took to social media at the weekend to say she condemned "bullying and thuggery".

Having defended this sort of conduct to a national television audience, how will McManus then seek to push employers with a straight face to tackle bullying and respect issues?

If you're going to invoke a principle with as glorious a heritage as one used by Martin Luther King, you should pick the right fights and get your facts straight.