Mystery of Robert Dickie's disappearance detailed in trial of Kylie So

That's what Justice Mark Ierace will have to determine as the trial of the New Zealand national accused of his murder continues.

After a week of discussions around the admissibility of evidence, on Monday, August 21, prosecution and defence outlined the cases for and against the accused, 50-year-old Kylie So.

Delivering his opening remarks at the NSW Supreme Court in Dubbo - where So is being tried without a jury - Crown prosecutor Liam Shaw argued So had a fight with Mr Dickie after he tried to kick her out of his Elong Elong home, resulting in his death.

However, defence counsel Ian Nash suggested there was not enough evidence to prove, beyond reasonable doubt, Mr Dickie is dead and it was "implausible" for So to have killed him and disposed of his body alone.

Mr Dickie was last seen alive by someone other than the accused on June 14, 2016. His sister, concerned for his well being, reported him missing two days later.

There have been no confirmed sightings of Dickie since and no activity on his bank accounts. Despite search efforts, no trace of his body has ever been found.

Throughout the course of the seven-week trial, the Crown will call So's brother and Dickie's neighbours, family, long term friends and former partners to give evidence.

According to prosecutors, Mr Dickie - a twice-married father of seven children - first met So in 2011 when she was a sex worker visiting Dubbo.

The two started talking again in 2016 and text and email records show Mr Dickie professed his love to her and invited her to come to Elong Elong to live with him.

So arrived in Australia from New Zealand on June 10 and then went to stay with Mr Dickie at his off-grid homestead on Wattle Road the next day.

A few days later, on the morning of Mr Dickie's disappearance, the pair visited one of Mr Dickie's neighbours who said he "looked away" when So told her she intended to stay permanently.

"The Crown case is that shortly after this visit ... it would be inferred that what happened was that Mr Dickie told the accused she could no longer stay with him on an ongoing basis," Mr Shaw told the court.

The Crown argued this led to an "altercation" in the bedroom which resulted in "a blood shedding event" and Dickie's death. They allege So then disposed of his body and mobile phone and then cleaned up the blood in the home.

Although there is no record of Mr Dickie telling So to leave, prosecutors argue he had a long history of short-term relationships with much younger women. Evidence from his computer and iPad showed he had made similar expressions of love to women from all over the world.

"Mr Dickie engaged in a lifestyle where he engaged with vulnerable women from the Dubbo and Forbes areas where he would have them stay in his home for short terms," Mr Shaw said.

"He would have sexual contact with them in exchange for money to buy drugs."

When police visited Mr Dickie's home the day after the alleged altercation, So was there alone.

She told police Mr Dickie said he was going to a party on the evening of his disappearance and he did not return. Police officers looked around the property at the time but did not notice anything suspicious.

However, the Crown said Mr Dickie's family members say it was "very unlikely" that he would have gone to a party as he was a "homebody" and a man of "routine and habit".

He said So's story had "inconsistencies" and what she told police about the party was "an endeavour to hide the true state of affairs."

But the defence told Justice Ierace the Crown's theory is "purely circumstantial" and cannot prove, beyond reasonable doubt, that Mr Dickie is dead or that So killed him.

Mr Nash said evidence which will be presented by the Crown to establish that Dickie and So may have had an argument which led to the death also pointed to different theories - including he was still alive.

"Of more importance is what that body of evidence says about the possibility of others being involved in his disappearance," he told the court.

"It raises the reasonable possibility, which cannot be excluded in a reasonable way, that other people may have been involved in his disappearance and death.

"He wasn't a man who loved routine ... there was an undercurrent in his life that he had a strong motive to keep secret."

Mr Nash also questioned the Crown's story that So killed Mr Dickie alone and disposed of his body in a way which led to no other traces than "half a dozen spatters on the wall" and blood stains under the carpet.

He added the Crown has no evidence of when the blood stains found under the carpet in Mr Dickie's bedroom came to be there.

"[There was] no trace of anything else in the house outside of the bedroom," he said.

"It's implausible, to put it bluntly."

Although he conceded the timing of Mr Dickie's disappearance looked bad for his client, he said that alone couldn't be proof of a murder.

"Co-incidences do happen," he said.

The trial of Ms So will resume at the Supreme Court in Dubbo on Tuesday, August 22 at 10am.

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