Scott Daniel Redman of South Lake was jailed for three years in May 2008 after he punched Mr Williams during an argument outside Cafe Kebab in Mandurah.

In its decision announced on Tuesday, the Prisoners Review Board noted there had not been any violent offenders’ treatment programs available to Redman in jail.

However, he had voluntarily attended the prison counselling service.

Among the reasons for the Board’s decision to release Redman included it being his first offence and he had a viable parole plan.

The Board ordered Redman have no contact with Mr Williams’ family and he undertake psychological counselling.

Dexter Williams’ mother Judith was disappointed after hearing the news Redman had been granted freedom.

“The release of Redman after serving just 20 months in prison for committing such a callous and tragic crime is difficult for our family to be okay with,” Mrs Williams said.

“His sentence was a pittance of a price to pay.

“It is Dexter’s loved ones who will pay the ultimate price in losing such a beautiful son.

“Rebuilding shattered lives is a journey that can last an unknown duration of time.

“Parole is a promise given by the prisoner that they will behave well if granted this liberty.

“Scott Redman has been granted this liberty of release, therefore it is our hope, that over time, he will become remorseful for his actions and that law and order will be high on his agenda.”

During his summary after the Perth Supreme Court trial, Justice Peter Blaxell said Redman had “exploded and committed an act which has had such tragic consequences”.

Justice Blaxell sentenced Redman to three years jail, reduced to two years under the truth-in-sentencing laws, for the punch on Mr Williams.

He also received a concurrent two years for the assault on Mr Williams’ friend Murray Smith who was also seriously injured during the attack.

The chain of events began when an argument broke out between Mr Smith and Redman after the navy seaman thrust his takeaway food into the face of a young woman.

Mr Smith confronted Redman over the incident.

Redman became angry, pushed Mr Smith backwards and punched him three or four times.

Mr Williams came to the aid of his friend but was punched by Redman.

Mr Williams regained consciousness two days later but died from a blood clot in his heart.