A man who punched his girlfriend in the head and then killed her uncle during a scuffle in South Australia's Far North has been sentenced to seven years behind bars.
Waylon John Cooley, 28, has been jailed for seven years for manslaughter and recklessly causing harm to his girlfriend.
Cooley stabbed the 37-year-old victim to death in Coober Pedy on July 4, 2019, during a fight.
The South Australian Supreme Court heard Cooley and his partner had been drinking at a gathering earlier that night, when the two began to bicker.
Cooley then left the gathering and his partner followed.
They began to fight in an unsealed carpark when Cooley struck the woman, who fell to the ground and was unresponsive.
"The act of punching [the victim] led to your conviction of recklessly causing harm," Justice Judy Hughes said.
Cooley's girlfriend's uncle — the victim — then stumbled across the pair in the carpark.
"[The victim] was quite drunk and was angry when he realised you had hit his niece," Justice Hughes said.
"[He] began pushing you and punching you and you began to retreat.
"He followed you and was punching you around the head from behind.
The victim died at the scene.
Cooley 'retaliated in anger'
Cooley turned himself into police two hours after the incident.
He pleaded guilty in the Port Augusta Magistrates Court to manslaughter last year, where he was acquitted of murder.
The jury found Cooley intended to cause grievous bodily harm to the deceased victim and acted disproportionately in self-defence.
Justice Hughes said the knife was a critical feature in the escalation.
Cooley's sentence was backdated to his arrest.
"Whilst [the deceased victim's] conduct was a separate incident I do not consider that [his] conduct substantially mitigated your conduct," she said.
"To say otherwise would be to suggest that his conduct warranted your attack with a knife.
"His conduct, though unnecessary and inappropriate, in no way justified or required the actions."
Cooley will be eligible for parole in two-and-a-half years.
Victim 'resting now in a better place'
Outside court, the deceased victim's mother told media she was not happy with the sentence.
"He stabbed my son twice in the arm and the neck," Lulu Boland said.
"It's not fair.
"My son was walking home and minding his own business.
"My son is in a better place than Mr Cooley."
The ABC has chosen not to name the victim due to cultural reasons.
