"Several witnesses saw the victim in this matter walking in the middle of the street," he said.
It was about 9pm when Miss Taurerewa sat down on Puriri St. A witness stopped and led her off the street and away from danger.
At 9.20 she returned and lay down on the road, and a passing motorist stopped and spoke to her, then pulled over, planning to get out of his car and help her off the road.
It was then that Wirihana and another motorist drove over Miss Taurerewa , and she sustained "serious injuries".
Both vehicles stopped and remained at the scene.
Mr Crowley said the second driver had not been charged, and Wirihana would not have been were it not for his breath alcohol level.
It was not known which vehicle in the incident killed her, which was why Wirihana had been charged with one count of driving with excess breath alcohol causing injury, rather than death.
"He has done everything he can to apologise to the deceased's family," Mr Crowley said.
"Not only have they accepted his apology, but they have encouraged him to attempt to forgive himself."
Since pleading guilty at the earliest opportunity, Wirihana had participated in a restorative justice conference with members of Miss Taurerewa's family.
The victim had three children aged 10, 7, and 5, the oldest of whom was receiving counselling.
Judge David Cameron said the victim was "the author of her own demise", and the circumstances were special.
"Her mother misses her daughter terribly but she's got the goodness of heart to want the defendant to forgive himself," he said.
"It's fair to say that this sorry tragedy has had a major influence on him."
He sentenced Wirihana to 100 hours community work and disqualified him from driving for 12 months.