"We accept that the officer should have taken more time to try to communicate with the boy to try to de-escalate the situation. However, we are satisfied that he did not intentionally provoke the situation; rather he believed the situation needed controlling quickly in order to keep the boy, the ambulance officers and the police officers safe, based on the volatile circumstances he was confronted with at the time," he said.
The investigation into the officer's actions came after two ambulance officers complained about the amount of force used.
The policeman was found to have used excessive force when putting the boy's arm up his back and choking him, the authority said in a report released yesterday.
Police had been called to find the boy about 7.30pm on August 25, 2013, after he had run away from Tauranga Hospital for a second time that night.
The teen had been admitted earlier that day following a suicide attempt.
He had fended off security personnel with a fire extinguisher and was reportedly drunk and under the influence of drugs when he ran from hospital earlier in the day.
The teen had a history of mental illness, suicide attempts, self-harming, and substance and alcohol abuse. The same police officers who had found the boy the first time were assigned to find him a second time and found him collapsed on Cameron Rd.
They called an ambulance as a precaution so the boy could be assessed before he was taken back to hospital.
The police officers accompanied the boy into the back of the ambulance and the ambulance officers later complained to the authority that police used excessive force in restraining him.
One of the ambulance officers, a paramedic with 23 years' experience, said the policeman and boy were swearing at each other and the officer provoked the boy with "a lot of verbal" which caused the boy to "lash out and retaliate". She said she had never witnessed anything like it before.
"He continued to ... choke the boy," she said, and explained how the boy's face began to change colour."
Authority chairman Judge Sir David Carruthers said the authority found that under the Mental Health Act the officers were justified in apprehending and detaining the boy but the actions of one of them escalated an already volatile situation.
"The officer did not adopt a strategy to effectively deal with the boy and de-escalate the situation."
Police would not reveal the officer's identity or comment on individual employment matters.