The ambulance officers complained to the authority that excessive force was used by police in restraining the boy.
Independent Police Conduct Authority chairman Sir David Carruthers said the authority found that under the Mental Health Act the officers were justified in apprehending and detaining the boy.
However, the actions of one of the police officers escalated an already volatile situation and was not good policing practice.
"Although the officer was entitled to use reasonable force to restrain the boy, the force used in putting the boy's arm up his back and choking him was excessive and contrary to law.
"It is clear to the authority that the officer, in speaking to the boy in the manner that he did, aggravated the situation and increased the likelihood that force would need to be used. The officer did not adopt a strategy to effectively deal with the boy and de-escalate the situation," Sir David said.
The authority noted that as a result of the police investigation into the incident, the officer involved had been subject to disciplinary proceedings.
However, due to the conflicting evidence the high threshold required for criminal prosecution was not met.