A drunken assailant mirrored his mother's behaviour by being "quick to violence" when he smashed a teenager's jaw at a popular Canberra car festival, a court has been told.
Karawera Te Kaitahi Mangu Rerekura, 29, was sentenced in the ACT Magistrates Court on Wednesday to a suspended 13-month jail term.
The NSW Central Coast resident had previously pleaded guilty to a charge of causing grievous bodily harm.
He committed the offence when a dispute erupted about vacant seats at a Summernats burnout show in January 2022.
Rerekura reacted to the war of words by punching an 18-year-old man in the face, breaking the teenager's jaw in two places.
The victim, who also had a tooth dislodged, later had screws and metal plates inserted into his jaw as part of reconstructive surgery.
Police managed to identify Rerekura, in part because the victim's girlfriend took a picture of the assailant and gave it to investigators.
Once he had been made aware of the fact officers wanted to speak to him, Rerekura phoned police and promised to return to the ACT and attend an interview.
He failed to do so, resulting in his extradition from the Central Coast in April last year.
Rerekura spent 17 days behind bars on remand before being granted bail.
While he pleaded guilty in September 2022, he disputed some of the facts of his offending.
Rerekura claimed the victim had pushed him, provoking him before he threw the punch.
He also denied having tugged on the victim's shirt to effectively square him up for the blow.
Magistrate Robert Cook ruled against the 29-year-old on both fronts following a disputed facts hearing last month.
Then, on Wednesday, Mr Cook imposed the suspended jail term and directed Rerekura to enter into a 12-month good behaviour order with supervision.
Prior to handing down the sentence, Mr Cook considered a court duty report and submissions from lawyers involved in the case.
Defence barrister Stephen Robinson, instructed by solicitor Anastasia Qvist, wrote in his submissions that Rerekura had endured an upbringing of severe disadvantage.
Mr Robinson listed 11 reasons, including that the offender's mother was an alcoholic and an addict who had been "seriously violent towards him".
While he accepted Rerekura's conduct had been "wholly unacceptable", Mr Robinson suggested his background explained it.
"The offender submits that there is a direct causal link between his upbringing of disadvantage and the offending," the barrister wrote.
"The connection is demonstrated by the factual similarity between the offender's actions in resorting to violence when drunk and his experience from a young age of violence with his mother."
Mr Robinson told the court Rerekura had, since the Summernats incident, quit drinking.
He had also started attending counselling sessions and "begun the task of fixing himself".
The court duty report indicated Rerekura was "able to verbalise significant victim empathy".
