Acquittal in South Australia single-punch death of Jack Hanley

Reece Watherston, who was accused of killing Jack Hanley with a single punch to the head, has been acquitted. Photo / News Corp Australia

An Australian man has been found not guilty of manslaughter after he fatally punched another man — now the victim's mother is seeking justice.

Reece Watherston was acquitted on Monday after pleading not guilty to the manslaughter of Jack Hanley, 22, who died after suffering catastrophic head injuries from a single blow during a drunken brawl in central Adelaide in December 2017, ABC reports.

The judge let Watherson free as he ruled he could have been acting in self-defence.

Watherston told South Australia's Supreme Court he never wanted to fight, but felt scared for his own safety after being knocked to the ground.

Watherston said he had been thrown on to the road before the confrontation, which happened shortly after 5am on a Sunday.

"Out of nowhere I've seen this huge, huge male approach me with clenched fists swinging at me," he said.

"I just remember seeing his fist go past my face and that's when I thought, 'Holy shit, I need to pay attention to what's going on here'."

He said he aimed his punch at Hanley's face "to get him off me and away from me ... I had to protect myself".

"I was scared, we were all scared."

However, the prosecution claimed Hanley was backing away when he was hit, but was struck with such force he would likely have been unconscious before his head hit the concrete pavement.

Jack Hanley, 22, was fatally struck in central Adelaide. Photo / ABC

In her verdict, Justice Anne Bampton accepted that Watherston inflicted the punch that caused Hanley's death, but found the prosecution had not satisfied her beyond reasonable doubt that she should reject Watherston's version of events.

"The punch by Mr Watherston constituted an unlawful physical assault upon the deceased carried out in circumstances where a reasonable person would have realised that he was exposing the deceased to an appreciable risk of serious injury," she said, in her written reasons for verdict.

"The prosecution has not excluded as a reasonable possibility that Mr Watherston, when confronted by Mr Hanley at approximately 5.20 am on 10 December 2017, fought back because he believed he had to, and that that belief was reasonable and genuine, and that his conduct was proportional to the threat he perceived."

The fatal punch was caught on security vision, but Justice Bampton declined to release it to the media.

Isn't my son's life worth more?'

When the verdict was read in court, the victim's family reacted in anger with his mother crying out "no".

Hanley's mother Julie Kelbin was distraught as she spoke outside court, and said her family had been denied justice.

"Where is the justice for my son Jack, who had never had a violent fight in his life?

"How many more deaths on our street is it going to take before our legal system starts to take this seriously?

The victim's mother Julie Kelbin was devastated and angry at the outcome. Photo / ABC

"This judge has just said 'go and live your happy life while this mother lives in misery'.

"How can a person kill another person with one punch [and] just receive a f***ing not guilty? Isn't my son's life worth more than this?"

"Every weekend someone is hurt in this city, when are we going to step up?"

Friend claims Jack Hanley 'wasn't fighting'

A friend of Hanley, Kalise Pansini, revealed that a fight had broken out on the night Hanley was killed, but claims the victim was not involved.

"I can't believe it, I can't believe we've gone through what we've gone through and they can stand there and say he's not guilty."

She described her friend as "the best person" and said he "[didn't] have a nasty bone in his body".

Reece Andrew Watherston refused to speak as he left court following the verdict. Photo / ABC

On his way into court, Watherston gave his condolences to the victim's family.

"Regardless of the verdict today my thoughts and condolences will always be with the Hanley family," he said.

"The 10th of December 2017 is something that will remain with mine and my family's life forever."

When Watherston left the court as a free man, members of the victim's family cried out at him, but he remained silent as he walked out.