A former economics department colleague said he found murder accused Clayton Weatherston easy to get along with but was aware he was ultra competitive in his academic work.
Prof Dorian Owen told the Christchurch High Court there was some suspicion in the department that Weatherston had chosen his subjects carefully to ensure his amazing academic record remained intact - he achieved A-plus marks in all but one of his papers.
''My impression was he thought he was very good, but I didn't think he was arrogant about it although I was aware others did,'' Prof Owen said.
The Crown agreed to allow Prof Owen to give evidence before Weatherston's own evidence has been completed in his trial for the murder of his ex-girlfriend Sophie Elliott.
Murder accused Clayton Weatherston will resume his evidence next week.
He was to have been back in the witness box today but extended legal argument and the calling of another witness meant there was insufficient time.
He has given evidence for more than a day so far but has yet to tell the court what he says happened in Sophie Elliott's bedroom the day he killed her.
The trial is now in its 13th day before Justice Judith Potter and a jury reduced to 11 members.
Prof Owen said he first met Weatherston in 2001 when he took over as his supervisor.
Weatherston went to work in Treasury in 2003 for nine months and finished his last research paper there.
He returned to the University of Otago in 2003 and Prof Owen said he worked closely with Weatherston on several research topics although he did not have a lot of peronal contact.
He found the accused laid-back and easy to get along with.
But he was aware of Weatherston's dissatisfaction about the marking of his dissertation.
''He was quite competitive and I told him if he wanted to be an academic he would have to get used to taking criticism,'' Prof Owen said.
Weatherston seemed to have no problems accepting ideas from him, he told the court.
He was aware of Weatherston's disputes with others in the department over issues of plagiarism and the alleged stealing of his ideas.
He told him it was not worth making a fuss over and if he did, it would be showing he was not an easy person to work with. But Weatherston wanted to take the co-authorship issue to mediation - ''he saw it as a matter of principle''.
''I advised him against it as it would create friction,'' Prof Owen said.
He became aware of Weatherston's involvement with Sophie Elliott about July 2007. He advised him against it and believed the accused had not fully thought through the consequences of having a relationship with a student.
Earlier today, legal submissions over some unresolved issues in the case caused a delay when Weatherston was to have resumed his evidence.
Justice Judith Potter released the 11 jurors until midday but counsel in the Christchurch High Court trial were not ready for the case to resume at that stage and Justice Potter sent the jury away again, this time until 2.15pm
Weatherston (33), a former University of Otago economics tutor, has admitted the manslaughter of his ex-girlfriend, Sophie Elliott, but denies what he did was murder. His defence lawyers say the charge should be manslaughter, that he reacted when Miss Elliott attacked him with a pair of scissors and lost control through provocation, that his narcissistic and obsessive personality rendered him unable to deal with the emotional pain Miss Elliott had caused him during their relationship.
During the frenzied attack, Weatherston stabbed or cut the 22-year-old honours student 216 times with a knife he had brought with him and with a pair of scissors.
The Crown says what he did was deliberate and premeditated murder, that the attack was persistent, determined and aimed at disfiguring aspects of Miss Elliott's physical beauty and attractiveness.
Weatherston began giving evidence late on Wednesday and was today expected to be asked about what happened in Mis Elliott's bedroom on January 9 last year when he killed her.
His evidence had reached late December 2007 when court finished yesterday.
