He found the cause of death was a brain injury due to failure to establish effective ventilation following his birth.
Whanganui District Health Board (DHB) director of nursing Sandy Blake said today the organisation was fully supportive of the coroner's findings.
"In New Zealand, maternity services are provided predominantly by independent health professionals supported by midwives employed by the DHB," she said.
Lead maternity carers were responsible for their own client outcomes, with their standard of work and professional development requirements set by the Midwifery Council and the College of Midwives, she said.
The Whanganui DHB had an agreement which allowed the lead maternity carers to access the DHB's facilities.
"When this tragic event occurred in 2004, Whanganui's maternity services were provided from a very old building.
"This has now been demolished and replaced by a new facility which has state-of-the-art birthing rooms and emergency call systems," she said.
Tane's family told Coroner Evans that Tane had trouble breathing from the outset and appeared to be blue and floppy.
However, Ms Baker recorded the baby's Apgar score - a measure of a healthiness after birth - as nine out of 10 a minute after he was born.
It remained nine when he was rescored five minutes later.
However, 15 minutes later, Tane had collapsed and was rescored a four. In the intervening time, Ms Baker had left the room to attend to the placenta and get an ice pack for Ms Brider. The length of her absence was disputed by Tane's family.
Coroner Evans found it more likely than not that she was out of the delivery room for 7-8 minutes.
The coroner found that Tane's state of respiratory distress began to evolve before Ms Baker left the room and continued for a further five minutes following her return.
Giving evidence, Ms Baker said if she had considered Tane was going to "go flat" she would never have left the room.
She had done so at the insistence of a family member, who wanted to take the placenta and leave.
Asked why she didn't call for another midwife to go to the room while she was out, she said the other midwife there had already told her she would be in another ward, and wouldn't be in the office if the bell rang.
"At the time it might have been a bad decision ... In retrospect, yes it was a bad decision," she said.
Tane's family gave evidence that he was in distress before she left, but Ms Baker said they all gave differing versions, 12 months after it happened.
Police decided not to lay charges against Ms Baker or anyone involved in Tane's treatment.
