A woman has told a jury in a murder trial her then-boyfriend "wouldn't stop" punching and kicking a man who later died of severe head injuries.
Paul Anthony Quinlan pleaded not guilty in the Brisbane Supreme Court on Monday to the murder of Scott Pilton, 48, on May 16, 2020.
Mr Pilton died in hospital from acute bleeding on the brain just over a day after he was allegedly fatally wounded by Quinlan on Lamb Island, north of Brisbane.
Crown prosecutor Michael Lehane in opening the case told the jury Mr Pilton, then 55, had been drinking with Quinlan at the home of the accused's girlfriend, Kimberley Lunt, on May 14.
"Mr Pilton was subject to one or perhaps more drunken, brutal attacks, at least one with murderous intent," Mr Lehane said.
Defence barrister Tim Ryan told the jury they had a critical matter to decide and that was whether or not Quinlan attacked Mr Pilton with intent to kill or cause grievous bodily harm.
"Was he, while drunk and angry, reacting without intent except to deliver a flurry of blows to a man he found in bed with his girlfriend and who made an insulting comment?" Mr Ryan said.
Ms Lunt was the prosecution's first witness and said Quinlan and Mr Pilton were in a fine mood as they drank alcohol in her lounge room on the night in question.
"Paul got up and I thought they were only play fighting. It seemed to get a little bit more than play fighting. I told him to stop, that he would hurt Scott," Ms Lunt said.
Ms Lunt, who had also been drinking on the night, said Quinlan repeatedly punched Mr Pilton in the face and kicked his legs but she could not recall how many times.
Mr Lehane asked Ms Lunt if Quinlan stopped when she requested.
"No. He was kicking and swearing. I didn't know what to do," Ms Lunt said.
She is due to continue giving evidence on Tuesday.
Mr Lehane had earlier told the jury they would hear there were no signs Mr Pilton had fought back against Quinlan.
"Mr Pilton left the house in an ambulance destined to die ... he never regained consciousness," Mr Lehane said.
The prosecutor told the jury they would hear during the week-long trial an audio recording of Quinlan's phone call to the ambulance service in which he claimed Mr Pilton fell down drunk.
"When asked if Mr Pilton was ever violent in the past, (Quinlan) replies, 'No, never. He's a beautiful man'," Mr Lehane said.
Mr Ryan earlier told the jury that they would hear Quinlan's version of events, which was that he found Ms Lunt and Mr Pilton in bed together and Mr Pilton told him to get out of the house.
Mr Ryan said Mr Pilton could have suffered a fatal head injury when he was dragged out of the bedroom by Quinlan and there was blood evidence to support this explanation.
