Judge rejects self-defence claim in murder

The claim the fatal stabbing of an unarmed Sydney father was an act of misguided self-defence has been dismissed by a NSW Supreme Court judge, who called out the killer's "web of falsities".

Khanh Xuan Pham's pursuit of Minto man Goran Stefanovic to continue the attack and subsequent dragging of the body back to his Sadlier unit were inconsistent with any perception he needed to act to save his own life, Justice Helen Wilson found on Tuesday

"I would not expect a man frightened for his life would pursue the danger," she said.

Pham, who'd pleaded guilty to manslaughter but denied murder, showed no emotion as he was found guilty of the more serious charge on Tuesday after a short judge-alone trial.

The judge found the 40-year-old's self-defence claims over the January 8, 2019, incident crumbled in the face of his dismembering of Mr Stefanovic's body and his acknowledged lies told to a neighbour, the victim's mother and police.

While the methamphetamine addict had consumed illicit substances before the murder, he had shown he was capable of rational thought and had a capacity to respond rationally.

After stabbing Mr Stefanovic once in the back when the father ended a call with a friend, Pham chased him out to the building's front steps to finish the job.

He and his girlfriend Kate Lloyd then dragged the body back into their studio apartment, with Pham telling a neighbour concerned about the trail of blood leading to the unit door that a dog had killed a rabbit.

Pham chopped up his victim's body, doing so in the bathroom where clean up would be easier, the judge said.

Cutting off Mr Stefanovic's ear and genitals in that process "speaks not to self-defence but to something much darker", Justice Wilson said.

Pham constructed a "web of falsities" by texting the victim's mother from the deceased man's phone "mum i had a little crash. Im OK" and claims that Mr Stefanovic was having a lot of fun with a wealthy, attractive nurse he'd just met.

Justice Wilson accepted the offender had general paranoia induced by intoxication and was worried someone posed a risk to him.

But that was evidence of general apprehension, not a need to kill an unarmed man to save his life, she said.

Pham will be sentenced at a later date.

Lloyd is currently in prison after pleading guilty last May to being an accessory after the fact to murder.