During a violent attack, Lee Price struggled to breath before collapsing outside his home.
Mr Price, 57, was unable to be resuscitated when paramedics arrived 45 minutes after an armed Craig Anthony Leahey's persistent assault and died of cardiac arrest.
Mr Price was morbidly obese, had a heart abnormality and was found with methamphetamine in his blood when he died following the September 2020 attack north of Brisbane.
Justice Peter Davis described Leahey's guilty plea to manslaughter as "very valuable", saying the Crown may not have been able to prove a connection between the attack and Mr Price's death.
He said the case was a difficult one to assess criminality, accepting the defence's submission that the force of Leahey's assault was "such that one would not normally expect death to be a result".
Justice Davis said Mr Price's obesity, heart abnormality and drug use put him at high risk of cardiac arrest, presenting a "complication of great significance".
"The Crown ... may not have been able to prove a causal connection between your assault ... and his death," he told Brisbane Supreme Court on Wednesday.
Leahey's defence explored the causal connection at a committal but a no case submission was rejected, the court heard.
"Ultimately you pleaded guilty to the charge of manslaughter. That has some significance here," Justice Davis said.
"By your plea you accepted that you caused Mr Price's death in circumstances where there was certainly arguments that the Crown may not have been able to prove that necessary connection."
The court heard Leahey attacked Mr Price weeks after another assault at the Booral residence.
The Crown said there was animosity between Leahey and Mr Price who knew each other through the local drug trade.
After striking a woman in September 2020, Leahey was told by Mr Price that he was "cut off" in heated discussions, the court heard.
More than a fortnight later Leahey arrived at Mr Price's home with another man and a weapon after drinking.
Mr Price came out of the house and was assaulted by Leahey who at one stage held the weapon to the 57-year-old's neck.
Mr Price struggled to breath as a woman and the other man tried to prise the weapon from Leahey during the assault.
At one stage Leahey chased Mr Price and the woman when they tried to escape.
Mr Price eventually collapsed and his face changed colour.
As Mr Price lay unconscious, Leahey told the woman not to call the police and left.
The woman waited 28 minutes before contacting emergency services who were unable to resuscitate Mr Price.
When police arrested Leahey they found 1.27kg of cannabis, the court heard.
Mr Price was described as a "much loved sibling, father and partner".
Leahey, 56, pleaded guilty to a number of charges including manslaughter and was sentenced to nine years in jail.
He will be eligible for parole in September, with 979 days in pre-sentence custody declared time served.
