Perth man not guilty of screwdriver death

A recreational fisherman has been found not guilty of murdering an Irish father-of-two by stabbing him in the head with a screwdriver during a fight next to Perth's Swan River over a "racist" remark.

Andrew Doan, 35, stood trial this week in the West Australian Supreme Court over the death of Charles John McCarthy, 32, in East Fremantle in the early hours of December 23, 2017.

Mr Doan was acquitted of both murder and the alternative charge of manslaughter on Friday after swift jury deliberations.

There were gasps and tears when the verdict was handed down.

Walking free outside court, the father-of-one told reporters he was shocked when he heard it, describing the past 13-and-a-half months in custody as a "crazy rollercoaster".

"I don't wish it upon anyone."

He wept as he said it was good to be back with family and friends.

The court heard Mr Doan and Tien Vu Huynh had been fishing without much luck for about two hours when Mr McCarthy walked by with his wife Nicole and friend Jason Mikel Curran, who made a remark about the Asian men getting into trouble with Fisheries for their catch.

Prosecutor James Mactaggart told the jury it was a "smart-arse, throwaway" comment that Mr Doan should have ignored.

But he was angered, believing it was racist because there was a stereotype "that all Asians catch undersize fish".

He followed the trio, who had been drinking at a Christmas function, as they walked away and sparked a profane, verbal argument.

Mr Doan, who was sober, then realised he was outnumbered when Mr McCarthy began "puffing up" and walked back towards him, "really staunch" with his fists clenched.

"It looked like he was coming into a demonic rage," Mr Doan testified.

Mr Doan, who is Perth-born to Vietnamese parents, told the jury he panicked, admitting he reached into his jumper pocket, pulled out a screwdriver he'd been carrying for crabbing and held it above his head, saying "get back or I'll stab you".

As he retreated to his car, Mr McCarthy charged and moved to punch him, but impaled himself on the screwdriver, which went through his temple.

Mr Doan said he had closed his eyes, threw his arms up to protect his face and forgot he was holding the tool.

He remained at the scene, telling police "it was me" and claimed self-defence.

That was accepted by the jury, who defence counsel Michael Perrella thanked on Mr Doan's behalf "for their wisdom and their common sense".

"There are no winners as a result of this trial," the lawyer said.

"Those that were present on the night ... will live with the consequences of what happened for the rest of their life."

Mr McCarthy's brother Dan and twin sisters Siobhan and Sinead travelled from their home in Cork, Ireland to watch the trial and did not comment as they left court.