A man embroiled in an ongoing dispute with his neighbour's friend broke the man's arm with a baseball bat after he claimed his car had been egged.
Jakson Mark Carmody, 30, was arrested after he attacked the man outside his Waramanga public housing property on June 11, 2015.
He and his partner had been involved in a series of disputes with the victim, who was a regular visitor to the house next door.
The man was leaving his friend's house after a late-afternoon beer when he noticed there was egg on the side of his car.
He approached Carmody and his partner at home and demanded to know who had thrown the eggs, sparking a heated argument.
Carmody said the man had kicked their letterbox and, fearing for his partner's safety, went inside and grabbed a metal baseball bat.
He emerged brandishing the bat and the men argued before Carmody struck the victim's left arm when he raised it to defend himself.
There was a cracking sound and the man's arm bent in a "deformed manner", causing him extreme pain, court documents said.
Carmody then swung the bat at two of the car windows, smashing the glass and causing the man's dog to leap from the back seat and run away.
He and his partner went back inside soon after before police and an ambulance were called. In an interview soon after his arrest, Carmody had denied he or his partner had thrown the eggs.
The victim was treated in hospital. His arm was shattered and doctors had to insert metal plates and screws in the first of two operations to fix the damage.
Carmody was charged and later pleaded guilty in the ACT Supreme Court to recklessly inflicting grievous bodily harm and property damage.
Prosecutors admitted during a sentencing hearing last month the attack was not planned, but argued there was a degree of premeditation given he left the argument to go and get the baseball bat "to mete out justice".
The Crown also argued it was "quite nonsense" Carmody had been concerned for his partner's safety when he left her outside to go and get the bat.
In his evidence, Carmody said: "I didn't sit down and write down my options and read them out and go, 'Oh well'. It was just a spur of the moment."
Justice Richard Refshauge, in remarks published this week, found the "vicious" attack wasn't premeditated and noted Carmody had only struck once.
"I am satisfied that Mr Carmody was motivated by a concern for his partner's safety and expressed the frustration that the ongoing problems he had suffered from the victim, despite the proper and sensible efforts that he had made to resolve the problems by other means, such as attempting to move house and calling the police, were behind the offence in this case.
"He agreed that he swung the baseball bat hard intending to hurt the victim and that he was in a rage."
Justice Refshauge said Carmody had a lengthy history of serious drug and alcohol use and his "challenging" criminal record showed he'd been found guilty of 47 offences, although none in the past five years.
While the judge accepted his behaviour was "generally out-of-character" and he'd made an enormous effort to reform since a previous stint in prison, he said there was a need to recognise the harm done to the victim.
Justice Refshauge indicated he would sentence Carmody, who had since moved to Sydney with his partner, to two years and six months imprisonment for the two offences.
But he adjourned proceedings so the offender could undergo an assessment for an intensive corrections order, which could mean he serves his sentence in the community instead.
Carmody will be sentenced in February.