John Torney, 41, watched via video link from prison as Melbourne magistrate Stephen Ballek ordered him to stand trial over Emma Bates' death.
But he left the video link room and refused to return for the formal committal process, where he was expected to be cautioned and enter a not guilty plea.
The 41-year-old repeatedly shook his head during Wednesday's hearing, where Mr Ballek found there was sufficient evidence for a jury to convict Torney of negligent manslaughter.
Torney has been charged over the death of Ms Bates, whose body was found at her Cobram home near the NSW-Victoria border on April 23, 2024.
She was allegedly struck to the head by Torney in the days before but a forensic pathologist determined diabetic ketoacidosis, a condition involving high sugar levels, likely caused her death.
Prosecutors told the court Torney still owed Ms Bates a duty of care and he should have called an ambulance when he realised she was not well.
But Torney's barrister Hayden Rattray argued a jury could not find Torney owed her that legal duty because they were not in a de facto relationship
It was also unclear when Ms Bates started experiencing the ketoacidosis so it could not be said Torney's failure to call an ambulance led to her death, Mr Rattray said.
Mr Ballek rejected those submissions on Tuesday, ruling a properly instructed jury could find Torney owed a duty of care to Ms Bates and he breached that duty by not calling an ambulance.
The magistrate said Torney and Ms Bates had been living together as domestic partners, noting he had a key to the house and they had described each other as boyfriend-girlfriend.
Torney knew Ms Bates had type 1 diabetes and that she monitored her condition through a glucose monitoring app on her phone, Mr Ballek said.
It's alleged Torney threw a glucose tester at Ms Bates when he found her moaning the day after he's accused of assaulting her.
He then left the home and went to the pokies instead of calling an ambulance, Mr Ballek noted.
"The accused chose to simply desert her," he told the court.
The magistrate said there was evidence of a sufficient weight for the case to go to trial in the Victorian Supreme Court.
He briefly left the bench so the parties could organise dates for the next hearing but when he returned, Torney had left his video link room.
Mr Rattray asked Mr Ballek for time to speak to his client, emphasising it was unclear whether Torney understood he was required to attend for the committal process.
Mr Ballek allowed the adjournment, with the case to return to Melbourne Magistrates Court on November 27.
Outside court, Ms Bates' sister Cassandra Searle told reporters she was relieved Torney had been ordered to stand trial.
Torney was in 2016 acquitted of murdering a toddler, after the two-year-old girl's beaten body was discovered in the roof cavity of a Mildura house.
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