A man has pushed for his negligent manslaughter charge to be dropped, arguing he did not hold a duty of care for a woman who died.
Emma Bates, 49, was found dead at her home at Cobram near the NSW-Victoria border on April 23, 2024.
She had allegedly been struck to the head by her neighbour and short-term partner John Torney, 40, in the days before she died.
But a forensic pathologist told Melbourne Magistrates Court diabetic ketoacidosis, a condition involving high sugar levels, was the likely cause of her death.
Prosecutor Matthew Cookson on Wednesday argued Torney still owed a duty of care to Ms Bates because they were in a de facto relationship, given they were intimate and living together.
Torney's barrister Hayden Rattray challenged that claim, arguing they had only been in a relationship for two to four weeks at the time of Ms Bates' death.
De facto relationships were akin to marriage, whereas their relationship was "extraordinarily short-lived" and "profoundly unhealthy", Mr Rattray said.
A jury could not find Torney owed her a duty of care because they were not in a de facto relationship, the barrister said.
He also challenged the prosecution argument Torney should have called an ambulance on the morning of April 22.
The court was told Ms Bates had a gash on her head, allegedly caused by Torney, and was moaning so Torney threw her sugar tester towards her.
Mr Cookson argued Torney breached his duty of care by not calling an ambulance when he realised she was not well.
"He doesn't need to know what's wrong, but he must have been aware something was wrong and he failed to act in the circumstances," the prosecutor said.
Mr Rattray argued it was unclear when Ms Bates started experiencing the ketoacidosis, so it could not be said Torney's failure to call an ambulance caused her death.
"He had no reason to expect she would not wake up," the barrister said.
Magistrate Stephen Ballek said he needed some time to consider whether the charge should be thrown out.
He will hand down his decision on November 19.
