Michael McHugh is the man who let NSW's dogs out.

The former High Court judge and advocate for the introduction of an Australian Bill of Rights could have been writing his own job description as special commissioner into greyhound racing when he called 10 years ago for agitators to question society's norms.

"Developed nations need agitators," McHugh told lawyers and students in 2005 on the eve of his retirement from the High Court after 16 years.

"Societies need interfering meddling people that question the rules and practices that most of the community accepts without question."

"The agitator is the perceptive listener who is not only aware of, and attuned to, the subtlest of accepted practices," McHugh said, quoting playwright Oscar Wilde. "The agitator notes when the entire ensemble – while in tune with itself – is playing in the wrong key."

McHugh, the agitator, practised what he preached as the commissioner in charge of the inquiry that prompted Premier Mike Baird to announce – after only one reading of the report – the end of greyhound racing in NSW.

Over the course of a year, the now 80-year-old McHugh reviewed 151,000 pages of documentary material, 115 hours of videos, about 2000 submissions, 59 responses, and examined 43 witnesses in 11 days of private hearings and 26 witnesses in 10 days of public hearings.

His conclusion was that one of Australia's oldest forms of recreation, greyhound racing, had turned a blind eye to cruelty, had lied to cover up its practices, and killed more than half of all dogs born every year.

Although McHugh and Baird have been hailed as heroes by animal rights groups, the former high court judge McHugh is said to love racehorses and a flutter.

As a boy, he owed his life to a horse called Rowdy who helped him escape a grassfire. "I just let [Rowdy] steer me through and we came out of it unscathed," he told The Newcastle Herald.  

Much later as a barrister and a Queens Counsel in Sydney, he was associated with the "legal eagles" syndicate that betted on horses. He was called "The Judge" by those on the track well before he was appointed judge of the Supreme Court of NSW in 1984 and later, in 1989, justice of the High Court.

McHugh was born in Cooks Hill, Newcastle, on November 1935, to an Irish Catholic working class family.

His dad started work at 15 in the mines and was determined that his bright son Michael get an education.

But the teenage McHugh fell in with teens who wanted to party as hard as six pounds a week in earnings would buy in the early 1950s.

He quit school. He delivered telegrams and worked in a variety of blue collars jobs, breaking his dad's heart. "He was very, very upset," McHugh told Fairfax. "He had great plans for me. He used to say to me, 'You'll wind up on the pick and shovel'."

McHugh married Jeannette McHugh, who won the seat of Grayndler in NSW, now held by Anthony Albanese. In 1993, she became a Minister for Consumer Affairs in the Keating Labor government.

After being admitted to the bar in his mid-20s, McHugh was ignored by the top end of town. They preferred to brief someone who had gone to Sydney University and a private school (not someone like McHugh, who earned his leaving certificate at night school in Newcastle). 

After moving to Sydney, he was most famous for representing Lindy and Michael Chamberlain in their appeals against their convictions associated with the death of their daughter Azaria, who they claimed had been taken by a dingo. They were ultimately pardoned.

On the High Court, his judgements included voting in recognition of native title in the case brought by Eddie Mabo. He often expressed surprise that this case didn't cause more controversy immediately.

His decision to uphold a part of the Migration Act that allowed the government to detain settlers "until" their refugee claims had been settled confounded his supporters. The case was brought by refugee, Ahmed Ali Al-Kateb, a stateless Palestinian who had been held in community detention.

"There is one area of law that provides fertile ground for the agitator … It is the continuing failure of this country to have a Bill of Rights," he said in 2005.

Without it, those on the High Court were not empowered to protect human rights in the same way as those on the Supreme Court in the US.

"That a judge may be called upon to reach legal conclusions that are applied with 'tragic consequences' were brought home in in the High Court's decisions of Al-Kateb v Godwin," McHugh said.

As much as he disagreed with what happened to the asylum seeker, he couldn't see his way around the language of the statute.

"If we had a Bill of Rights, the results may have been very different," he said.

Later he said that a judge's decisions shouldn't be thought to reflect their own personal views, but the law.

"My own social views are probably as radical as anyone in this room – maybe more so," he said.