There were gasps from the public gallery and Sophie Elliott's father and another man walked out of the High Court at Christchurch yesterday, when Clayton Weatherston's lawyer suggested Miss Elliott's mother was not a reliable witness because what she saw the day her daughter was killed must have traumatised her.
"With great respect and due deference to her . . . but what she saw on that day must make her a less than reliable witness as far as details go.
"I don't want to say that, but I do because I have to," Judith Ablett-Kerr QC told the jury during her three-hour closing address at the trial of Dunedin academic Clayton Weatherston.
Weatherston (33) is accused of murdering Miss Elliott (22) at her home on January 9, 2008.
He has denied murdering her, but admits her manslaughter.
He is arguing he was provoked into killing Miss Elliott.
In his two-hour closing address, Crown prosecutor Robin Bates said Weatherston at his trial had tried to "rewrite history" to avoid responsibility.
His stories varied when told to different people, and he constantly shifted the blame for bad things in his life to other people.
In the days before Miss Elliott's death, he had told her he wished she was dead and told other people he hated her.
When Weatherston went into Miss Elliott's bedroom with a knife and locked the door, he had done it because he had clearly decided to kill her and did not want to be disturbed.
When he calmly turned around and relocked the door in the face of Miss Elliott's mother it was because he did not want to be disturbed while he finished what he had set out to do.
This all indicated the crime was premeditated, Mr Bates said.
He questioned Weatherston's psychological problems, saying the anxieties and insecurities he experienced were normal and the level of grandiosity he exhibited was not a trait of a narcissistic personality, but quite normal for someone of his talents.
The fact he had no remorse and still blamed Miss Elliott for what happened was an indication he had achieved what he had set out to do.
Mrs Ablett-Kerr said Weatherston was clearly not normal.
His unusual personality characteristics left him unable to cope with the difficult relationship he had with Miss Elliott over several months, she said.
"Dr Weatherston was like a coiled spring, and the trigger that unleashed that spring and set it loose was what happened in that room."
Naturally, Miss Elliott would not have known that the way she expressed herself could have led to what happened, she said.
Weatherston had a future ahead of him, so why would he do such a thing on purpose? Both lawyers said it was the jury's job to set aside emotion and use their common sense.
They should not think about how Miss Elliott was killed, but whether Weatherston was provoked to the point where he lost his self-control and killed her.
Mrs Ablett-Kerr said a person could know what they were doing, be focused and still have loss of self-control.
It was called dissociation.
A psychiatrist had already testified Weatherston had dissociated himself during the killing.
After the judge's closing address this morning, the 11-person jury will begin deliberations on whether Weatherston is guilty of murder or manslaughter.