Victim: Anthony Zervas

Victim: Anthony Zervas Photo: Supplied

The only man found guilty of the murder of Anthony Zervas in a violent brawl between rival bikie gangs at Sydney Airport has had his conviction set aside and will face a retrial.

Mahmoud "Mick" Hawi was found guilty by a NSW Supreme Court jury of the murder of Mr Zervas, who was bludgeoned with a bollard and stabbed in the chest and abdomen in the departure hall on March 22, 2009.

Hawi, who was also found guilty of affray, was sentenced to a maximum of 28 years in prison with a non-parole period of 21 years and six months backdated to May 2009 when he was first jailed.

On Friday, the Court of Criminal Appeal in a majority decision quashed Hawi's murder conviction.

The Chief Justice, Tom Bathurst, said he could not be satisfied beyond a reasonable doubt that Hawi inflicted fatal blows to the head of Mr Zervas using a bollard and that it was not open for Hawi to have been convicted on that basis.

He also allowed the appeal on the grounds that the jury's verdict convicting Hawi did not reconcile with the verdicts acquitting the other five members of the Commanchero motorcycle club of murder.

Justice Bathurst said he would have entered a verdict of acquittal but, given the lack of consensus with the other two judges - one of whom would have ordered a retrial and one of whom would have dismissed the appeal - he decided to concur with the retrial option.

Justice Derek Price found it was open to the jury to be satisfied beyond reasonable doubt that Hawi deliberately struck Mr Zervas' head with a bollard which substantially contributed to his death. But he found there was reasonable evidence of provocation and the trial judge should have allowed the jury to consider provocation as a partial defence.

In a dissenting judgment, Justice Lucy McCallum held that Hawi's conviction, when considered alongside the acquittal of other Commancheros, did not entail any miscarriage of justice. She also did not find the trial judge erred in declining to leave provocation to the jury.

The original trial ran for nine months.

During the trial, the jury heard that the Commancheros and Hells Angels assembled at the airport after being contacted by gang members on a plane from Melbourne.

Hells Angels chapter president Derek Wainohu, who was on the plane, and felt intimidated by Hawi and other Commancheros present, sent a text for help and, in response, a number of Hells Angels, including Mr Zervas, went to the airport.

There were a series of scuffles in which 12 Commancheros confronted five Hells Angels.

During the brawl, Mr Zervas was stabbed several times and bashed on the head with a bollard.

The jury heard that DNA matching the profile of Hawi was found under Mr Zervas's fingernails.

Hawi's retrial will be held at a date to be set.

Mr Zervas' mother, Frederika Bromwich, told Fairfax Media she was "hurt" by the NSW Supreme Court's decision.

"I am disgusted," she said. "I don't understand. I've got to go back to court and go through all this again? I'm trying to get some normality back in my life."

Mr Zervas' death strained relations between Ms Bromwich and her older son Peter. The pair have not spoken in years and Ms Bromwich said she lost two sons in that airport brawl.

"I don't think you can describe what has happened," she said. "It's just a nightmare that doesn't end."