"Clayton is an extremely honest and sensitive person. He tells the truth; we all tell the truth," his mother, Yuleen Weatherston, told the Otago Daily Times yesterday.
Many of the things they learned about their son during his murder trial in Christchurch made sense in hindsight, she said.
"We were very sad not knowing the psychological and physical abuse Clayton was suffering in his relationship with Sophie, and the effect that was having on him.
"To us, he was simply looking forward to a bright future."
Weatherston (33) was found guilty of murder last Wednesday after a four and a-half-week trial in the High Court at Christchurch in which he argued Miss Elliott had provoked him.
When asked about an article in the Herald on Sunday yesterday, Weatherston's father, Roger Weatherston, said he had concerns about the way some of his comments had been reported.
In particular, he felt a comment about being "ambushed" by Sophie Elliott's mother, Lesley Elliott, who had hugged Mrs Weatherston outside the lifts in the Christchurch court building after the verdict was delivered, had been taken out of context and did not reflect the family's "true feelings".
The ambush comment had not been meant in a mean-spirited way; in fact, his family had barely even thought about the hug, he said.
He denied saying provocation had been the only defence left for their son and that they had not ruled out an appeal.
He had referred the reporter to his son's lawyer on that matter, he said.
Mrs Weatherston said it was true the couple had battled with some of the "inaccuracies" that had been reported.
Because their son was an honest person, they believed their son's account of his relationship with Miss Elliott.
They were private people and felt it was inappropriate to make any further comment until after their son's sentencing.
Mr Weatherston said it had been "really hard" even to read out a short prepared statement after the trial.
They had recorded a television interview about their son before the trial because they felt, at that time, that was their best opportunity to show people who their son was, he said.
Meanwhile, Mrs Elliott told the Herald on Sunday her daughter's killer should spend the rest of his days behind bars.
Mrs Elliott said Weatherston had taken the most precious thing from their family.
"That was our daughter and sister . . . For that, I think he needs his life to be taken. I don't mean capital punishment. My thoughts are that he should lose his freedom for the rest of his living life."
Otago University has said it will review its staff-student relationships policy.
It required supervisors to disclose any conflicts of interest, including family, financial and/or sexual relationships with a student or colleague.
That had happened in the case of Weatherston, who had been Miss Elliott's economics tutor.