On his own version Andrew John Cobby was with his wife when she was beaten on a Gold Coast hinterland street.
But for three hours after her bloodied body was found Cobby failed to inform or warn their children who were in a house nearby.
He failed to use his mobile phone to call emergency services for help.
And the now 59-year-old failed to run to the safety of his car or neighbouring houses for aid and protection.
Cobby pleaded not guilty in the Brisbane Supreme Court to murdering Gaylene Cobby - known as Kym - who he called the "love of his life".
The couple had been married for more than three decades, but mostly lived apart from 2003 onwards.
Ms Cobby was repeatedly struck on the head with a hammer then strangled to death outside her Worongary home on November 12, 2017.
Cobby admitted being present when his wife was attacked, but told police an unknown assailant was responsible.
He told police - in interviews played during the 15-day trial - the couple had been threatened and faced demands for millions of dollars.
"I have four individuals trying to extort money, but I couldn't pay them," Cobby told officers.
The trial heard Cobby had accepted money to trade on the stock market in return for "risk-free bonuses".
Investors didn't receive paperwork for handing over up to $170,000, one told the court.
People, including a private investigator, had been to the house Ms Cobby shared with her mother and brother-in-law looking for Cobby over the years, defence barrister Tony Kimmins told the jury on Wednesday.
Ms Cobby's mother told the trial she had banned Cobby from visiting their home.
She was concerned Ms Cobby could be attacked for her relationship with Cobby because he was taking money from people.
Mr Kimmins said even Ms Cobby's family members recognised there was a real prospect that as a result of Cobby's frauds victims would "take matters into their own hands".
"And as a result Kym Cobby would be attacked because she was hanging around with him," Mr Kimmins said, adding the jurors needed to be certain she wasn't "collateral damage".
But crown prosecutor Phillip McCarthy said Cobby's story to police was "just rubbish".
If Cobby's version was to be believed the lives of himself, Ms Cobby and their children were in danger.
Instead Mr McCarthy argued the only person on the street that night who needed protection was Ms Cobby.
"And the only person she needed protection from was Andrew Cobby," he said in his closing address.
The Crown argued Cobby ran and hid after the attack to prevent immediate detection, taking time to "get a story together" before returning his son's phone call three hours after Ms Cobby's body was found by her brother-in-law.
The jury saw footage of police interviews with Cobby, but Mr McCarthy says the versions change and his story "however remarkably performed by him is simply untrue".
Cobby's jeans and shirt were left bloodstained during the attack that occurred near a red Chrysler he had driven to the house.
Ms Cobby's head wounds were consistent with being inflicted by a hammer found near the vehicle.
Mr McCarthy said there is no support for Cobby's claim he lost consciousness during the hours before he phoned his son or that he was hit on the head by the attacker while trying to protect Ms Cobby.
Mr Kimmins is expected to continue his closing address on Thursday, before Justice Peter Callaghan addresses the jury.