A father from South Australia's Aṉangu Pitjantjatjara Yankunytjatjara (APY) Lands cried uncontrollably after learning his attempts to punish his son had led to the teenager's death, a court has heard.

Adelaide's District Court is preparing to sentence Duncan Jowel O'Toole, 41, who pleaded guilty to manslaughter over the death of his son in August 2021. 

O'Toole stabbed his 19-year-old son — who cannot be named — three times in the thighs following an argument about his son wanting a computer game. 

The court heard his son became agitated during the argument and struck him. 

The teenager presented at the Ernabella clinic in the remote Indigenous community of Pukatja with stab wounds before being flown to Alice Springs Hospital, but died from his injuries the following day. 

On Tuesday, O'Toole's lawyer Greg Mead SC told the court his client wanted to punish the teenager, which was consistent with a modern form of traditional Aboriginal punishment.

"Ultimately these injuries led to his son's death — a reality that continues to haunt Mr O'Toole," he said. 

The court heard O'Toole cradled his son on his lap immediately after the offence while sobbing and crying.

The teenager tried to take the blame following the incident, saying his wounds were self-inflicted, which the court heard was consistent with the traditional forms of punishment.

Mr Mead said his client was genuinely remorseful for his actions. 

"His remorse is so genuine that his estranged partner and family, who lost a well-loved son, grandson and nephew, accepted that Mr O'Toole was genuinely remorseful and extended their forgiveness and love to him," he said. 

Mr Mead asked Judge Emily Telfer to impose a merciful sentence, saying his client was living in squalor at the time and was struggling with a lack of support in the remote area in caring for a child with an intellectual disability and challenging behaviours.

Prosecutor Chris Edge said O'Toole should have recognised that the limited medical assistance in the APY Lands made his actions all the more dangerous — and that his actions stopped just short of murder.

O'Toole will be sentenced at the end of the month.