KEY POINTS:
Throughout his illustrious law career, Justice Peter Mahon was at ease in delivering the most stirring of speeches and fiercest of verbal barbs.
Air New Zealand was famously the target of one of his finely crafted deliveries, when in 1981 he accused it of an "orchestrated litany of lies" stemming from the Erebus air disaster - a quote ensuring his place in New Zealand's history.
Yet when it came to speaking to his own son, artist Sam Mahon, words did not come easily for this respected High Court judge.
The pair communicated mostly at a distance through letters.
It was only towards the end of his life, after public battles with Prime Minister Robert Muldoon and the legal establishment over his Erebus findings, that Justice Mahon opened his heart to his oldest son as he lay ill in his bed in his Auckland home.
Sam Mahon was about to embark on a difficult new chapter of his life with partner Caroline. He had tried to keep it secret from his father because "I knew it would worry him".
"But he had figured it out anyway.
"He said to me in plain terms: 'Caroline is an intelligent and beautiful woman. You two get on very well together. If you want to be together, you shouldn't worry about hurting other peoples' feelings. You only have this one life.'
"And when he told me this, he couldn't look at me. He was looking just past me, because it was an intimate thing, right? And then I gave him a hug. Because what could I do? He had given me his blessing.
"I could feel him stiffen under the hug - like 'Jesus Christ, are you some kind of homosexual?'
"That was the only time I remember hugging him. This generation of men that had been through the war, whatever it was had cauterised them emotionally and they couldn't do it."
Sam Mahon - accomplished writer, painter, sculptor, conservationist, living in a cavernous converted flour mill in the rural isolation of North Canterbury - is in many ways everything his father was not.
So it might seem strange the 54-year-old has written a soon-to-be-published book about his father.
But it is something he believes only he could do. And something he felt he should do.
My Father's Shadow is more a memoir than a biography because of a lack of detailed information, and consequently "it's me and him", Sam Mahon says.
When he died in 1986, Justice Mahon was "one of the 10 most admired New Zealanders", and to Sam Mahon, "the bravest person I have ever met".
While most will remember him as the man who held Air New Zealand to account over the Erebus tragedy that claimed 257 lives, he left his mark as one of the country's great legal minds.
In the mid-1950s he was Crown Prosecutor in the infamous Parker-Hulme murder case, when he described the two young killers as "dirty-minded little girls".
There was much more to him than his life as a judge, Sam Mahon says.
He and his father shared the same "bloody-mindedness" and love of nature. But Justice Mahon was a "chameleon", mixing effortlessly between all kinds of people, while Sam Mahon always felt awkward and out of place.
Justice Mahon's love of horse racing, whisky, cigarettes, and his support for the 1981 Springbok tour, were all things Sam Mahon stood against.
He says it would have done no good to try to debate these issues with his father. "How could you fight a man whose words were like razors? My father spoke clearly and almost ponderously. I speak in a blur, and it's almost impossible for people to hear what I'm saying at times.
"I remember sitting at the table sometimes and he would say 'what did the boy say?' And my mother would have to interpret for me."
Sam Mahon feels no sadness for not being closer to his father. The relationship was what it was.
"We were kind of combative in a way. When I was about 12 years old, I think my father just looked at me and said 'well this guy's not going to be an All Black, he's not going to be a lawyer' ... so he left me alone, which is great.
"And that's one of the biggest gifts he gave me. Most of the other kids I knew ... were very aware of the expectations their parents had on them."
While many blame the treatment after his controversial Erebus report for driving the judge to an early death at 64, Sam Mahon does not.
"Erebus was a gift for him. I think he was bored on the Bench.
"I remember watching him on TV - 'Oh, there's the old man, being interviewed again'. Because I knew him, I would watch his face and say 'yes, he's tired today' or 'he's on form today'."
The judge's health was already deteriorating, with a heart attack in the years leading up to his death.
"I can't imagine he'd go quietly into that good night. He'd have fought the whole way no matter what. Whether Erebus killed him, I don't know. Possibly 64 years is what he had."
He remembers clearly his father's utter rejection of evidence given from people in the Erebus inquiry that he knew to be wrong.
"In my life as a kid, if I had ever taken that stance, I would have been in deep shit. My father drew very, very severe lines. I knew exactly where the parameters were. I never lied to him."
After his Erebus report - pointing to a computer navigation mistake rather than pilot error - was found by the Court of Appeal to be a breach of natural justice, Justice Mahon not only suffered through loss of reputation, but also through the loss of friends that could no longer afford to associate with him.
Sam Mahon recalls his father being pitted against "second-rate minds" like Muldoon, who also refused to accept his findings, finally tabled in Parliament in 1999.
"When I used to listen to my father talking to his colleagues, for instance, it was like being at school. I was learning stuff. And when I listened to politicians I learned nothing.
"He said at one stage in one of his reports that in his role as a commissioner he was required to descend into the dust of battle. And there was plenty of dust. He might also have said 'into dirt'.
"He was required to descend to their level to defend the dead pilots and their families. He couldn't let go of it. I think that is why he took interviews and went on television and continued the fight with Muldoon.
"Taking on Muldoon, to my mind, would have been a piece of cake [compared with] walking on to a minefield to pick his friend up who had had his feet blown off. I don't feel he was afraid of Muldoon or anybody."
Sam Mahon could have spent much longer and written hundreds more pages about his father.
Like every painting and sculpture he has done, the book "feels unfinished". But he knows it is the best he could do in the circumstances.
He wrote one chapter about his parents meeting. His mother reviewed it and came back saying it was all wrong. She rewrote 12 pages.
But Sam Mahon says this simply reflected that the story was being told in his own way.
"I make it very clear to the reader that [my father] would not approve of some of the passages ... but I feel it's necessary to craft the portrait of him, in the same way as if it was a mole on his face and I was painting him.
"There were flaws in the man of course, but I don't dwell on them."
It does not really matter to him how his father is remembered.
"All I require of any of my life is that people have a look at all the evidence and make up their own minds."
My Father's Shadow - A Portrait of Justice Peter Mahon, Longacre Press, on sale Aug 29, $39.99.
SAM MAHON, ON HIS FATHER JUSTICE PETER MAHON:
While out hunting, on the eve of his Erebus report being released:
"Peter standing with his gun broken over his arm, with the characteristic cigarette, staring out across the grey broken water, surrounded by the leafless willows and waiting for gunfire. 'Tomorrow all hell's going to break loose'."
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"Some believe that the Erebus inquiry and its aftermath unravelled his health. That may be so. But he was an artist in his way and Erebus was his masterwork. It is inconceivable that he would have turned down the challenge of untangling that extraordinary mystery."
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Hunting snakes while with the occupation forces in Japan in 1946:
"It is odd that he would hunt these creatures. After all, he had one as a pet back in the barracks. A thin crimson-mouthed grass-snake called Dave that he cherished ... there was always this duality: the hunter and the lover of nature."
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"He travelled to New Orleans once simply to hear some old-time jazz. But he had left it too late. They were playing new tunes by then, smart licks, a little too experimental for his taste. No one was playing The Basin Street Blues anywhere."
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"The law suited him. It suited his wit, it suited his sense of gamesmanship as well, for after all, he was a strategist, a card player. 'Cut it out Samuel,' he once said when I had been dicing the pack a little too long, 'you'll shuffle the tits off the queen'."
