Woman convicted of fatal NSW stabbing

A woman who fatally stabbed her boyfriend in the thigh with a kitchen knife during an argument in NSW told police he tripped and fell on the blade, a court has heard.

Shane MacDonald bled to death in January 2015 after he was found with a 9.5cm-deep stab wound to his upper left thigh at a bushland campsite at Wonboyn, in southern NSW.

His partner of six months, Judith Thelma Blanks, told witnesses at the scene and later police that Mr MacDonald had tripped and fallen on to a log where the blade was resting upwards, the NSW Supreme Court heard on Friday.

But prosecutors said Blanks, an alcoholic with a history of violent outbursts, had been chopping vegetables when she got into an argument with Mr MacDonald and lashed out with the knife.

That scenario was accepted on Friday by Justice Peter Hall, who convicted Blanks of manslaughter following a judge-alone hearing in February.

Blanks was declared unfit for trial last May.

At February's hearing two recreational fishermen testified they heard Blanks swearing and yelling at Mr MacDonald over several hours leading up to the incident.

A hiker saw the couple drinking beers and said they appeared drunk.

When Blanks raised the alarm that afternoon, the fishermen had gone to the couple's aid, one, Chris Jones, telling the court they came upon a "horrific scene" with blood everywhere.

Mr MacDonald appeared unconscious or dead and Blanks explained, "he fell over a log on to a knife", the court heard.

An autopsy revealed the 15cm knife had severed Mr MacDonald's artery and he died from massive blood loss.

A forensic pathologist's report found Blanks' explanation not plausible based on the angle of entry of the blade and other factors.

Justice Hall noted Blanks had a history of spontaneous violent eruptions and said that while he was satisfied she stabbed Mr MacDonald, the charge of murder couldn't be proved.

"I am not satisfied beyond reasonable doubt that at the time of the stabbing, that the accused had any intention to kill the deceased or to inflict grievous bodily harm upon him," Justice Hall said.

Blanks is due to face a sentence hearing on April 28.