"I'm making this movie so that nobody is under the illusion that I've been coerced into what I've done," said Mrs Mott. "Or I've been murdered, or for that matter, committed suicide. I am euthanising myself."
Part of the reason Mr Mott was discharged without conviction yesterday was that Justice Courtney considered his culpability to be low.
"Rosie would have taken those steps with or without your help," she told him.
But a critic says the judge's ruling sets a dangerous precedent.
Before the sentencing hearing, Mr Mott told the Herald that Parliament should change the law so that voluntary euthanasia was an option for the terminally ill or those with an irreversible condition, like his wife.
"For Rosie to be that sick and to die alone by her own hand, that's not right. Our family should have been around her to say goodbye."
Labour MP Maryan Street has drafted a bill to legalise euthanasia, but it has not been drawn in the ballot that decides which private members' bill go before Parliament.
Three out of five New Zealanders - 63.2 per cent - would back such a law change, a Herald-Digipoll survey found.
More than a quarter of those surveyed - 26.8 per cent - opposed any change.
Mr Mott's discharge yesterday was met with applause from a court gallery packed with friends and members of his family.
Rosie Mott was diagnosed several years ago with an aggressive form of multiple sclerosis, a degenerative condition for which there is no cure.
The 55-year-old's health deteriorated rapidly and her husband agreed to help research suicide methods and assemble a kit with which she could kill herself.
Mrs Mott waited until the birth of a grandchild late last year and spent a final Christmas with her family before deciding to end her life.
She asked her husband to leave her alone in their Auckland home, and he returned hours later to find her dead.
The Herald revealed the charge against Mr Mott in April and he pleaded guilty a month later.
Assisting suicide carries a maximum penalty of 14 years in prison but Mr Mott's lawyer, Ron Mansfield, yesterday asked for him to be discharged without conviction.
Mr Mott is an internationally recognised boatbuilder, and was worried that he would miss out on job opportunities if he could not travel, particularly to the United States.
"For this man to move on, he needs to work overseas and a conviction will create difficulties. It's a blight he would have to explain forever," said Mr Mansfield.
"This man has suffered enough. A conviction doesn't compare with the trauma he has endured."
Justice Courtney ruled that the consequences of a conviction for Mr Mott would be out of proportion to the gravity of the offence.
But she said her decision was based on the particular circumstances of his case, which was different from other assisted-suicide prosecutions.
The judge was satisfied Mrs Mott decided to take her own life and Mr Mott's culpability was low.
A conviction would cause "great difficulties" for Mr Mott in working overseas. Because of his age, he did not have many working years left.
He did not have a criminal record, was unlikely to offend again, was of good character, had told the police everything and pleaded guilty at the earliest stage.
"You acted out of love and in support of your wife," Justice Courtney said. "I wish you well."
A spokeswoman for the Family Life New Zealand lobby group said the discharge set a dangerous precedent for future cases of assisted suicide.
"[Justice Courtney] has opened the door for others to assist in suicide and not suffer any consequences," said Colleen Bayer.
"This decision also flies in the face of New Zealanders' concern over the high suicide rate in our country."
