A "smart-arse" remark angered a woman enough to give Bradley Breward's location to his accused killer, a jury has heard.
Tina Robertson gave evidence during the third day of Mark Rodney Jones' Launceston Supreme Court trial.
The West Launceston man has pleaded not guilty to murdering Mr Breward at a Newnham unit on New Year's Day in 2017.
On the day of the alleged murder, the court heard Ms Robertson was leaving her boyfriend Cody Lee's unit when Mr Breward insinuated she'd had sex with another man.
"Brad was pretty much trying to ask if I f---ed Elfie," she said.
"He was being a smart-arse."
The court heard Mr Breward laughed after he made the remark to Ms Robertson, so she walked to her car and called Mr Jones.
Mr Jones' Nissan Patrol had been stolen and he had been looking for Mr Breward in relation to the theft.
Ms Robertson told the accused Mr Breward was lying on the couch at hers and Mr Lee's Parklands Parade unit.
"I told him not to do anything to Brad or Cody," she said.
Ms Robertson said she was offered a $1000 reward by Mr Jones to tell him where Mr Breward was.
Defence lawyer Greg Richardson asked Ms Robertson if her motivation for setting Mr Breward up was for money, but she denied setting him up.
"I wanted Brad to get help," she said.
The court heard Ms Robertson was initially motivated by money, then she was motivated by a flyer that said there was a $5000 reward for the return of the car because it seemed legitimate and her final motivation was anger over comment Mr Breward made.
Ms Robertson met Mr Breward after he contacted her via Facebook Messenger saying he could sell her ice much cheaper than what she was paying for it, the court heard.
A police interview conducted with Mr Jones on January 20, 2017, was played to the court on Wednesday.
Mr Jones told police he'd been searching for Mr Breward in relation to his stolen Nissan Patrol, but "I didn't find shit".
Mr Jones said the search included trips to Hollybank, Ravenswood and Bracknell, but he stopped looking for Mr Breward just after Christmas.
The trial before Justice Robert Pearce continues on Thursday.