Damien Dickie remembers searching his missing father's rural home, before a person began climbing a locked gate.
He was asked on Thursday if he could remember what they looked like.
"Similar to the person sitting over there," Mr Dickie told the New South Wales Supreme Court on Thursday in Dubbo, where Kylie So, 51, is on trial after pleading not guilty to murdering his father.
She was extradited from New Zealand in 2020, where she returned about two weeks after travelling to Dubbo, and then to Robert Dickie's 36-hectare property at Elong Elong in central west NSW, where he bred piglets and pitbull pups in June 2016.
The 71-year-old disappeared while Ms So was staying at his property and no trace of him has been detected since.
They first met in 2011 when he engaged her as a sex worker.
The pair began communicating again in March 2016 and she returned to Australia four days before he was last seen.
She claims he left to go to a party, leaving the property with others and never returning.
Mr Dickie told the court he noticed the pigs were not in their pen, and thought his father's dogs were overfed when he arrived at the property on June 16, 2016.
He travelled from Cessnock with his then-girlfriend after a concerned call from his aunt.
Under cross-examination, Mr Dickie said police told him not to think about what he suspected from "day one".
"I thought (the dogs) ate my father, yes ... an evil person had done it," Mr Dickie said.
So's barrister Ian Nash suggested Mr Dickie's theory was a result of him thinking about what happened to his father since he disappeared more than seven years ago, because he only mentioned one of the dogs in an early statement to police.
Mr Dickie said he formed his theory on the day and contended his father's disappearance was not his primary focus.
"I had a lot of things going on at that time mate," Mr Dickie said.
His own son Dylan disappeared a week after Mr Dickie travelled to his father's Elong Elong property.
An inquest in 2022 found the 19-year-old may have taken his own life, died by misadventure, or with the involvement of a third party, after his motorbike, helmet and gloves were discovered in a forest 10 days after he vanished.
Police investigations have not found any connection between the two disappearances, crown prosecutor Liam Shaw said when opening the prosecution case.
The judge-alone trial resumes on Monday.
