Grabbing a crowbar, Michael Trevor Royce Collins left his apartment to "put the wind up" two men who he believed had mocked him as they walked past.
"Then it all went wrong," defence barrister Victoria Trafford-Walker told a Brisbane Supreme Court jury on Thursday.
Following a heated exchange, Collins and his mate Harley Hoodless left his first floor apartment to confront the two men on the street.
Collins only wanted to scare Shannon Finemore and Scott McGillivrey, Ms Trafford-Walker said.
However, Mr Hoodless allegedly punched Mr Finemore in the head, causing him to fall to the ground unconscious.
Days after the 2020 Melbourne Cup night incident in Brisbane's Fortitude Valley, Mr Finemore, 37, died from injuries caused by the blow, the court heard.
Collins had been arguing on his apartment balcony with his partner about what they should have for dinner when Mr Finemore and Mr McGillivrey were walking past.
Collins believed the two men were mocking him and there was a "back and forth" over the balcony with Mr Hoodless also yelling, the court heard.
"It's clear that either Shannon Finemore and/or Scott McGillivrey invited them down by saying 'come down here you f***ing c***s' or something similar," Ms Trafford-Walker said.
"He had an argument with his partner in the privacy of his own home and these two men inserted themselves into the situation by mocking him."
Crown prosecutor David Finch said Collins and Mr Hoodless had a common intention to unlawfully assault Mr Finemore and/or Mr McGillivrey when they confronted them.
But Ms Trafford-Walker said if Collins wanted to hurt someone he would have used the crowbar.
"At no point did he use it," she said, noting that Collins kept the crowbar by his side throughout the confrontation.
Collins told police that he had the crowbar as a "scare tactic".
"It was a good outcome. I walked around and I saw the shock, horror look on their face," he said in a police interview played in court.
"If I was going to hit him with it I would have just walked out, cracked old mate on the head."
Collins tried to de-escalate the situation, verbally and physically attempting to stop Mr Hoodless before the fatal punch, Ms Trafford-Walker said.
"What more could he do?" she said.
"Going downstairs and grabbing the crowbar is where ... the poor choices (by Collins) ended.
"It went wrong because Harley Hoodless went off on his own."
Moments after the alleged punch, the court heard, Mr Hoodless told a passer-by: "I just f***ed that guy up."
"Mr Hoodless was acting on his own accord on this night," Ms Trafford-Walker said.
Collins stayed and tried to help Mr Finemore after the punch while Mr Hoodless ran and hid, she said.
Collins, 30, pleaded guilty to going armed to cause fear.
He has pleaded not guilty to unlawful striking causing death at the trial before Justice Melanie Hindman.
