Gregory Merriman, 58, was housed at the Metropolitan Remand and Reception Centre in Sydney when a fight broke out among his fellow inmates on December 27, 2022.
CCTV of the incident shows the Yuin man was not involved in the brawl - in which one man was wielding a pole - but appeared to try and break it up before retreating towards his cell.
Mr Merriman was metres away when a correctional officer deployed capsicum spray to diffuse the fight before the inmates were locked in their cells, the inquest into his death was told.
No one checked on him until nearly half an hour later when he was found unresponsive in his cell. He could not be revived.
An autopsy found Mr Merriman died of a heart attack.
"His death adds yet another death to the tragic toll of Aboriginal deaths, of men and women who have died in custody," counsel assisting Jake Harris told the inquest on Monday.
He noted there have been 600 such deaths since the Royal Commission into Aboriginal Deaths in Custody handed down its findings more than three decades ago.
"Greg, of course, is much more than a statistic," Mr Harris said.
Key issues under consideration include whether Mr Merriman's health issues were appropriately managed in custody and whether the use of capsicum spray was a reasonable use of force.
Mr Merriman had "significant health issues", including a severe coronary artery disease and had suffered a heart attack years earlier, the inquest was told.
One of his fellow inmates told the inquest he heard Mr Merriman saying he wasn't feeling very well after the capsicum spray was deployed in the prison wing.
"I could see he was affected by the spray," he said.
But two experts are expected to tell the inquest it was unlikely that the spray had contributed to Mr Merriman's death.
The capsicum spray made it "instantly hard to breathe" and had been deployed in response to a brawl over holiday cookies, another inmate said.
Mr Merriman was a peacemaker who successfully managed to keep everyone calm for days before tensions finally boiled over when extra cookies were given to some inmates, the inquest was told.
"It wasn't until an argument over cookies that things kicked off," inmate Gregory Webber told the inquest.
"It was a couple of days in the making but that was the straw that broke the camel's back."
Hours later, Mr Merriman was declared dead.
He had became stuck in the "revolving door" of jail after surviving institutional abuse at a young age, his brother Mark said in a statement.
"Greg was a larrikin and a kind man," he said.
"I don't want youth to go down the path Greg (did) because in this system, the consequences could be death."
The inquest before Deputy State Coroner Harriet Grahame continues.
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