'I've shot him,' woman tells slain husband's friend

David Borg thought the bang of a slamming door woke him after he had fallen asleep watching TV, until a long-time friend's wife revealed she had just shot him.

"She said, from memory 'call an ambulance, I've shot him. I was going to shoot myself, but I shot him'," Mr Borg told a jury on Wednesday.

Dale Vella, 54, has pleaded not guilty to murder and is facing a NSW Supreme Court trial after shooting her husband of 23 years.

Mark Anthony Vella, 52, was killed at their Murrumbateman home in the state's southern tablelands in August 2021.

Mr Borg said he could see blood from the doorway of his friend's bedroom, but he could not go inside.

"I think I said to Dale, 'you're going to jail', and then I went and got my phone," he said.

It is not disputed Vella shot her husband through the eye with a shotgun as he slept, however the jury is considering her state of mind at the time.

If it finds she had a substantial mental impairment she could be found not guilty of murder but convicted of manslaughter.

Her guilty plea to manslaughter was rejected by the Crown.

Vella's barrister Greg Hoare told the jury on Tuesday she was coerced and controlled by her husband "incessantly" for years, which destroyed her emotionally and psychologically.

Justice Helen Wilson warned jurors they would likely have an "emotional reaction" to a recording of Mr Borg's triple-zero call, played on Wednesday.

While on the phone, Mr Borg fetched the couple's daughter from another building on the property.

"Your mum's just woken me up and said she's shot your dad," Mr Borg said.

"I'm not joking," he told her.

Georgia Vella said she was falling asleep when Mr Borg arrived, puffed and in shock, and she snatched the phone from him.

The call records her distress after finding her father.

"His face is blown out," Ms Vella is heard telling the operator.

She stayed on the line for several minutes waiting for help to arrive, while her mother told her she meant to shoot herself.

"Don't say that s***," Ms Vella recalled telling her.

Mr Hoare asked for a break as the recording ended while Vella cried in the dock.

Ms Vella told the court when it resumed she learned her mother was prescribed antidepressants four days before her father's death, was sleeping all day and not eating much.

She told her daughter she was "not doing well".

Vella had also told Mr Borg she was depressed, but not why, he said.

The couple had been arguing about money and their business, and Mr Borg acknowledged Mr Vella and was known to have a quick temper.

"But he cooled down just as quick," Mr Borg said.

He had never seen or heard of Mr Vella being physically violent, and his relationship with his wife seemed "OK" in the months before his death.

Mr Vella "wasn't an easy man to live with", his daughter said.

"He would get angry and verbalise how he felt, walk away for 10 minutes and he'd come back fine."

However, she also never witnessed any physical or emotional violence.

"Mentally I was not affected by my father, I cannot speak on my mother's behalf," she said.

Vella's older son, who worked with his stepfather in the family air-conditioning business, is due to give further evidence on Thursday.

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