A man accused of unlawfully killing a stranger by punching him and stomping on his head during a bar fight joined the brawl to rescue his cousin, a Perth court has heard.
New Zealand man Jed Beaumont, 33, was in a coma and died at Royal Perth Hospital on May 11 last year, three weeks after he was allegedly attacked by 24-year-old Hubert Benjamin Humes.
The West Australian Supreme Court heard on Wednesday Mr Beaumont and a friend were leaving the Commercial Hotel in Northam, 97km northeast of Perth, on April 17 last year when they were confronted by a group of people and a fight broke out.
Humes is accused of punching Mr Beaumont in the face, causing him to fall back and hit his head on the pavement, and then stomping on Mr Beaumont's head as he lay unconscious on the ground.
In his opening address, prosecutor Bernard Standish said in an interview with police Humes admitted punching the victim but denied stomping on his head.
He said Humes told police he was grabbed around the neck and then he "knocked that man out".
Mr Standish said an autopsy revealed Mr Beaumont, who worked as a chef at Yongah Hill Detention Centre, died from head injuries sustained when he was punched.
Defence lawyer Paul Sullivan told the jury his client joined the fight when he saw his smaller cousin get punched, adding he only hit the victim once during the scuffle.
"The accused effectively rescued his cousin," he said.
Humes has been charged with manslaughter, but the jury has the option of finding him guilty of the lesser charge of unlawful assault causing death.