Brodie Graham Champion, 21, came before the High Court at Dunedin yesterday where he was jailed for two years after pleading guilty to the manslaughter of Grant Jopson.
Justice Rachel Dunningham said it was an "extremely difficult decision" whether to impose imprisonment or home detention.
After the hearing, the disgruntled families of both parties took aim at the justice system.
The Jopson family, in a statement, said they were re-traumatised first when the Crown dropped a murder charge and then when the possibility of home detention was raised.
"Sentencing is supposed to denounce the criminal, hold him to account for the harm he has caused, and deter others from committing the same offence.
"We don’t believe any of this has been achieved in this case."
Brenda Gamble said her husband of 33 years was a good guy.
"Grant was fiercely protective of his family and he died protecting us.
"The trauma and grief has ripped my insides to pieces."
"In this country people shouldn’t be able to come into your property to attack you, and you’re not allowed to do anything to defend yourselves ... all you can do is dial 111 and hope like hell they get there in time."
Her son was haunted by the events of the past year.
"He keeps saying ‘Mum I was forced into a situation and they made me take someone’s life’.
"He talks about how broken he is because he never had a real dad growing up and he took someone else’s."
In the weeks before the killing, Champion was driving in Mosgiel and mistakenly believed his 22-year-old neighbour was involved in a road-rage incident.
On October 15 last year, he confronted Ms Gamble as she walked a dog, swearing and yelling at her.
Champion gave her a "threatening message" to pass on to her son and when she told her husband what had happened he left the house.
"Right, I am going to sort this out," Mr Jopson said.
On seeing him and his son arrive, Champion dashed inside his house and grabbed a 20cm kitchen knife.
Mr Jopson told the man he had been wrong about the earlier driving accusations and urged him to put down the weapon.
When the defendant backed off, waving the knife in front of him, the father and son followed.
Mr Jopson armed himself with an aluminium broom and hit Champion a few times, during which the head of the implement fell off.
His son threw a terracotta pot, which found its mark.
After being cornered, Champion was "swinging the knife around wildly", and lunged two or three times, the court heard.
Mr Jopson sustained a stomach wound and collapsed on the grass.
"I can’t breathe, I can’t breathe, it hurts," he said.
The defendant immediately admitted to police he had stabbed the victim.
"I warned them," he said.
Crown prosecutor Craig Power said a term of imprisonment was warranted to "mark the sanctity of life".
Champion’s counsel Sarah Saunderson-Warner argued home detention was still a significant sentence, and was appropriate given her client was deemed a low risk of reoffending.
Character references described him as kind and generous, someone who had never displayed aggressive tendencies, she said.
Justice Dunningham accepted there was "an element of self-defence" involved in Champion’s actions and noted he had no history of violence.
A psychological report shed light on the defendant’s family background of instability which had led to a diagnosis of PTSD, she said.
Ms Gamble spoke of the pain of being without her partner.
"Grant was a loud character and made his presence known.
"The silence of being alone is hard to bear.
"My poor Grant. He wasn’t supposed to die."
