One-punch attacker had been banned from Adelaide CBD, court told

A man who left another man in a coma with one punch had been banned from entering Adelaide's CBD when the attack happened at a city nightclub, a court has heard.

Jason Lindsley suffered a severe head injury after being knocked down by Ali Joubouri inside Zhivago Nightclub in Currie Street in August 2012.

The prosecutor told the District Court the then 21-year-old Joubouri should not have been in the city, let alone at the nightclub.

He had been banned from the CBD and going out after 9:00pm because of earlier offending, the prosecutor said.

The court was played security camera vision of the attack during sentencing submissions.

It showed Mr Lindsley fall to the concrete floor after being punched, before Joubouri ran away.

Prosecutor Kos Lesses said Joubouri put down two drinks he was holding before the attack.

"The prosecution says it was a deliberate and skilful punch. It was a strong, sudden, forceful punch delivered without warning," Mr Lesses said.

Joubouri's lawyer Jon Lister said someone had called his client a "faggot wog", before he turned around and spoke with Mr Lindsley.

"It was a remark he acknowledges made him angry ... and it was offensive," Mr Lister said.

"The footage shows Mr Lindsley leaning down towards my client's ear and saying something immediately before the punch is thrown.

"My client says that he believed in the circumstances he was being threatened.

"If the remark had not been made Mr Joubouri would have continued his dance."

Mr Lindsley cannot remember anything about the attack.

Victim suffering post-traumatic stress disorder

Mr Lister said his client had already spent more than a year and a half in jail, and should be released immediately when he is sentenced in December.

"It is now time for Mr Joubouri to be released back into the community with appropriate support and perhaps on strict conditions by way of a bond to continue with his rehabilitation."

But the prosecutor argued Joubouri should spend more time behind bars.

Mr Lister said his client was suffering from post-traumatic stress disorder at the time after being stabbed a few months earlier by three hooded men.

The victim's father, Doug Lindsley, said it was hard to see vision of the attack.

"Your heart jumps out of its skin, you get a lump in your throat ... and you get a cold sweat and you think my son could have died," he said.

"Let's hope ... justice comes forward, not only for this but for people that go out there in the future so that we can set a precedence and show him that you can't do this and get off with it."