Murder accused Clayton Weatherston was ill-equipped to deal with the situation he was in because of his unique personality make-up, the High Court at Christchurch heard yesterday.
Defence counsel Judith Ablett-Kerr QC said in a brief statement to the jury that the emotional pain of the "torrid and tumultuous relationship" between the former University of Otago economics tutor and one of his students was behind the fatal stabbing of Sophie Elliott.
As a result of his unique personality make-up, Weatherston was provoked into losing the power of self-control and killing Sophie Elliott in January last year.
Mrs Ablett-Kerr said the effects of the relationship had impinged not only on Weatherston's personal life but also his professional life and "culminated in the horrific events of January 9".
Miss Elliott had attacked him with a pair of scissors and he responded.
The jurors would need to focus on the behavioural aspects of both parties and decide what the "proper level of legal culpability" was in the case.
The defence contended it was manslaughter, Mrs Ablett-Kerr said.
Her statement identifying the issues the defence said were important followed the Crown opening address in which Marie Grills set out the evidence to be called about what happened the day Sophie Elliott was killed and what led up to it.
Weatherston and Miss Elliott had been in a relationship since the middle of 2007 when she was an economics student completing her honours degree and he was lecturing in the department and finalising his PhD.
The relationship would be described by Sophie's mother, Lesley Elliott, as an "up and down" one, either "all on or all off", Mrs Grills said.
It was effectively over by the middle of December, after Sophie returned from a holiday in Australia, but there was still some contact between the two, including an incident in late December when Miss Elliott said she was assaulted by Weatherston.
She had gone to his flat to give him an album of photographs she had taken of his graduation and he became amorous, suggesting they go to the bedroom "for old times' sake".
Evidence would be that Sophie told her mother and friends Weatherston threw her on the bed and straddled her, but that she had struggled and managed to get away, Mrs Grills said.
And there would also be evidence he made a comment about how he had prayed the aeroplane bringing her back from Australia had crashed, killing her.
Weatherston also told her he wished she was dead as she had ruined his chances of getting a permanent job he had applied for as a lecturer in the economics department and he was "giving all his hate" to her.
Miss Elliott told people she had considered going to the police but decided it was "not worth it", as she was going to Wellington soon, Mrs Grills said.
She also told friends she had spoken to Weatherston on Monday, January 7 at the university.
He had denied the incident at his flat and, in her frustration, she indicated to him what he had done by putting her arm across his throat.
