The estranged wife of convicted murderer Tony Worrell said last night she regretted not doing more to make him stay home the night he drove into two cars in a drunken, suicidal rampage.

Lynette Worrell, now living in Brisbane, said she still believed her husband was "absolutely drunk as a skunk" and did not intend to deliberately kill anyone or commit suicide.

But this week Worrell sobbed out loud and trembled as he was found guilty of murdering 26-year-old Katie Powles and causing Brett Robinson grievous bodily harm in June last year.

He was also found guilty of two charges of attempting to cause intentional damage.

On the day of the incident, Worrell had spent the afternoon getting drunk while Lynette, his wife of 20 years, was out.

When she returned, they argued and Lynette told him she wanted him to leave. She gave him a deadline of the end of the week but instead Worrell threw some belongings into his car and took off.

Just after 7pm that night, Worrell - an open can of beer between his legs - hurtled down a South Auckland road at speeds estimated to be as high as 125km/h. Four cars swerved out of his way but Karaka man Brett Robinson wasn't so lucky. His Fiat Uno collided with Worrell's car and rolled. Only the seatbelts saved his life and those of his sons.

A few seconds later Worrell ploughed into Katie Powles' red Mazda 323 head on. She died that night in hospital.

Lynette Worrell, a neonatal nurse at a Brisbane hospital, said she regretted not doing more to stop her drunken husband leaving.

"Hindsight is a wonderful thing. He is responsible for his actions. It is hard to rationalise with someone who is not listening."

She said Worrell had tried to get help for his alcoholism "but he didn't stick at it, unfortunately".

Lynette said she was "quite surprised" by this week's murder verdict.

"Obviously the prosecution did a better job than the defence," she said.

She believed the conviction should have been for manslaughter because there was no doubt he had caused the death of Powles.

Lynette had not spoken to the families of Powles or Robinson but had sent cards.

"I felt I wanted to let them know how sorry I was for what happened to them."

The Worrells came to New Zealand from Australia in 2004 to support their son, whose young son had developed a rare cancer.

The family are now back in Queensland and her grandson had recovered, Lynette said.

She worked as a neonatal nurse at a Brisbane hospital and looked after the couple's two dogs.

While she had spoken to her former husband on the phone, Lynette said her life was now in Brisbane and she would not visit him in prison.

Worrell understood what he had done, she said. "The whole thing is enormously sad - there are no winners here."