An Auckland man who has spent the vast majority of his adult life behind bars has been ordered to return to prison again, this time for acting so intimidatingly towards a new acquaintance that the much smaller man felt compelled to jump out of a moving vehicle - a decision that was fatal.

Mesi Teo had been released from his latest prison stint for just seven days in April 2021 when Kimleang Youn, a 28-year-old from Cambodia known by the nickname “Hang”, fell head-first on to a Māngere street.

Jurors in the High Court at Auckland found Teo guilty in November of manslaughter and failure to stop and ascertain injury.

As he returned to court today for sentencing, Teo himself estimated that he has spent only about “one year and a bit” of his adult life outside of prison walls, while the rest of it has been spent serving time for his more than 75 previous convictions.

Justice Michael Robinson noted that much of Teo’s prior offending had been for violent or threatening behaviour. The judge ordered a sentence of four years and nine months’ imprisonment for the manslaughter charge, and a sentence of four years’ disqualification from driving for the failure to stop conviction.

“Mr Youn was a lot smaller than you - no doubt, a lot weaker than you - and he was in a vulnerable position,” the judge noted.

Prosecutors said during Teo’s trial that he was guilty of “fright response” manslaughter, which occurs when someone’s behaviour causes another person to act in a way that causes their own death.

Teo and Youn had met on the same day of the incident, when they both showed up at a mutual friend’s home. Teo was looking to score methamphetamine and Youn was looking for a pipe to smoke his own supply, so they paired up and drove off together, prosecutors Anna Devathasan and Rob McDonald alleged.

But later, as Teo drove past a store where he had agreed to drop off the passenger, Youn asked where they were going and unlatched his seatbelt, prosecutors said.

Kimleang Youn died weeks after he was ejected from a moving vehicle in April 2021. Photo / Supplied

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“I know you have drugs inside your pockets,” Teo then responded, according to a friend of the defendant who would later testify that Teo confessed to him.

When Youn repeated that he had no more drugs on him, Teo is alleged to have responded, “What about I check your pockets?” before patting down the passenger’s thigh.

That is when prosecutors say Youn jumped out of the vehicle, estimated to be travelling over 40km/h. He suffered critical injuries and died weeks later.

In a victim impact statement read aloud in court today, Youn’s mother described how she is haunted by the memories of her son gasping for air after he was taken off life support - a medical team having decided he could not recover from his injuries.

“He was my life and my entire universe,” the grieving mum wrote. “My heart broke into a million pieces... My entire world shattered.”

She described her son as someone who was a loyal friend and quick to “laugh and smile and try to cheer others up”. While he may have had his faults, he will always be her baby, she said.

“How cruel can a person be to be remorseless for his wrongdoing?” she said of the defendant.

Teo continued to contend today, as he did throughout the trial, that he was falsely convicted - the victim of a conspiracy by police, the court and witnesses to torture, humiliate and damage him.

Evidence against him had included the friend who said Teo confessed, Teo’s DNA detected on the outside pocket area of Youn’s pants, CCTV footage showing Teo with the van in the same area about 15 minutes before the incident, another witness whose testimony suggested Teo had a pattern of acting in a “domineering way when he’s in a moving vehicle” and a recorded call between Teo and his father that took place one week after his arrest.

“How is it my fault if he jumps out of my car? I didn’t hold a gun to his head and tell him to jump,” Teo said in Samoan, according to a translated transcript of the call. “God knows I didn’t push him out.”

Prosecutors emphasised that it wasn’t necessary for Teo to have pushed Youn. As a much larger man in a confined space, Teo’s “veiled threat” triggered a fight or flight response in his passenger and there was nowhere else to go, they successfully argued to jurors.

Prosecutors said today that Teo had taken advantage of the victim’s good natured manner, which resulted in Youn offering to give the defendant gas money and share his drugs with the stranger. Teo’s response, McDonald said, was to act in “a domineering, forceful way”.

Teo represented himself throughout the trial but allowed standby lawyer Todd Simmonds to address the judge during the sentencing hearing. Simmonds noted the defendant didn’t appear to have planned the incident and he didn’t have a weapon.

Simmonds also pointed to Teo’s self-reported upbringing, which included moving to New Zealand from American Samoa when he was 8 years old and frequent moves throughout Auckland in the years that followed.

Teo claimed to have been involved with the criminal justice system since the age of 10 and said he participated in ram raids and burglaries as a child. He also claimed to be the victim of savage beatings by family members - including having his head stomped and being hit over the head repeatedly with pool cues.

He was a teenager when his first prison sentence was imposed.

“The institutionalisation - the in and out of prison - ...is a relevant factor,” Simmonds said. “For the better part of 20-plus years, Mr Teo has spent the vast majority of his time in a prison environment.”

Prosecutors, however, asked the judge to exercise caution in evaluating anything relying only on the defendant’s word. The judge agreed that there were concerns about the reliability of some of his statements.

Today’s hearing marked the end of a case that was repeatedly beset by oddities and delays, including a spectator who was accused of approaching jurors outside the courthouse to give his opinion of the case and frequent disputes outside jurors’ presence in which Teo repeated that he was being unjustly persecuted and threatened to privately prosecute court staff, investigating officers, media and lawyers.

On more than one occasion, jurors were sent home early as Teo told the judge outside their presence that he was sick or dizzy due to post-traumatic stress disorder triggered by his arrest. Justice Robinson often implored him to stop talking over lawyers and himself.

Teo remained silent for most of today’s hearing until he was invited by the judge to speak on his own behalf. The judge did, however, have to constantly remind him that he wasn’t being invited to re-litigate the case.

“I’m unfairly being sentenced - I just want you to be mindful of that,” Teo responded. “They’re trying to shove something down my throat that I didn’t commit, and that’s obvious...

“I don’t even want to ask you to sentence me on something I didn’t do ... but if you do decide to sentence me on this case I ask you to do so in fairness ... and with mercy, sir.”

He asked the judge to consider an alternative sentence such as time served or home detention.

The judge declined.