NSW man jailed for manslaughter of ex

A NSW man who stabbed his former partner to death, hid her body in a bush, and then drank beers with another of her ex-partners, will spend at least five and half years in jail for manslaughter

In a murder trial in February, Robert Bruce Smith was found guilty of the lesser charge of manslaughter for the 2018 killing of mother-of-three Karine Farrell near Nambucca Heads.

Smith's legal team successfully argued the then 56-year-old was acting in excessive self-defence when he stabbed the woman after she brandished a one-metre metal pipe at his head.

During the trial the jury heard the pair had ended their year-long relationship the day before when Ms Farrell punched Smith in the face while he was driving after he allegedly made insulting remarks.

Ms Farrell had a history of abusive behaviour, had been drinking and was "irate" when she dropped by Smith's house to return a pair of boots the afternoon she was killed.

When the argument from the day before resumed, she retrieved the metal pole from her car boot, prompting Smith to arm himself with ornamental knives.

In the hours after the attack, Smith told police he ran at Ms Farrell to "scare her", but stabbed her repeatedly with the two knives after she swung the pole at his head.

In returning their manslaughter verdict, the jury agreed that Smith's actions were self-defence, Justice Michael Walton said when sentencing Smith in the NSW Supreme Court on Monday.

The judge also noted Smith suffers from post-traumatic stress disorder, as a result of a violent childhood and training in the armed forces, which would have played a role in his reaction.

"The circumstances encountered by the offender ... were quite fast-moving, dynamic and emotionally charged," he said.

"The encounter on the previous day, where he was driving the vehicle and during which he was punched and bled profusely would have contributed to a sense of fear."

But the jury also deemed Smith's actions were excessive, Justice Walton said, and they left Ms Farrell's family to suffer profound and ongoing grief.

However, Smith had demonstrated he was remorseful, despite his actions after the killing, Justice Walton said.

After dragging Ms Farrell body under a hedge and moving her car, Smith washed the two knives and his clothes.

When her other ex-partner dropped by after she failed to return home, Smith said he didn't know where she was and the pair drank beers metres from where her body was hidden.

Smith similarly lied to another person and to police when they first asked if he'd seen her, Justice Walton said.

But Smith's willingness to plead guilty to manslaughter before trial, which the Crown rejected, his rehabilitation in prison and several apologies showed he was indeed remorseful.

Justice Walton found Smith had reasonably good prospects of rehabilitation, and sentenced him to seven years and six months jail.

He will be eligible for parole in five year and six months and, factoring in time served, will be eligible for release on November 17, 2023.