Rohen James Hanson, 41, pleaded not guilty to murder over the death of his partner Dee Annear in a bush hut in September 2021.
He admitted her manslaughter, telling a NSW Supreme Court jury he had acted in self defence when tackling Ms Annear into a wall after she swung a beer bottle at him and charged.
Hanson falsely claimed in a triple-zero call and then to police that his partner had been injured in a ute accident and later died at the hut, jurors heard during the trial.
On Tuesday, Justice Peter Hamill discharged the jury after it failed to reach a unanimous verdict despite 22 hours of deliberations.
Prosecutors alleged during the trial at Coffs Harbour that Hanson and Ms Annear had a fraught relationship.
The couple had reconciled for the camping trip after a violent argument in which she received black eyes, the jury was told.
After her death, forensic examination found Ms Annear had multiple injuries consistent with blunt-force trauma.
The killing was a "significant bloodshed event", prosecutors said.
Hanson admitted to police that he tried to wipe up blood in the hut and hide a bloodied mattress in the bush, the court was told.
"I threw it out because it looks like I f***ing murdered her and I just started s****ing myself," he allegedly said.
After the jury was sent home, Justice Hamill extended his sympathies to the family of Ms Annear as they sat in court.
"I thank you for your quiet vigil over the proceedings, it's been noted," he said.
Hanson will return to court on June 7, when a new trial date may be set.
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