Police have acknowledged making mistakes during the pursuit of a motorcyclist who was left with a brain injury but say the man involved is not owed an apology.
Dion Batt, who was 34 at the time, crashed into a traffic island during the pursuit in West Auckland in 2010. He suffered a severe brain injury requiring long-term treatment
An Independent Police Conduct Authority report into the pursuit found the operation was fraught with problems and breaches by police.
Assistant Commissioner Upper North police, Allan Boreham, says one officer has been punished and changes to police policies have been made since.
"We take professionalism very seriously and when our staff don't get it right then there are consequences and they are held accountable.
"These people are out there trying to protect the public in a very difficult situation. They've got to get their judgements right. They didn't get it right; that's reflected in a public document."
Mr Boreham says Mr Batt had methamphetamine in his system when he crashed.
Mistakes on both sides - mother
Mr Batt's mother, Sharon, says her son is solely dependent on carers.
She says despite the mistakes that were clearly made by the police, her son doesn't blame them for what happened.
"Dion himself, his words this morning, was 'no-one's to blame for what happened to me. It was my fault'.
"We support the police in everything and everyone can make mistakes and the fact that the faults have been recognised through this investigation and are being addressed by the police is great."
But she believes the outcome would have been different had police followed correct procedures and stopped their pursuit.
Police reached 120 km/hr
The IPCA report said the pursuit started when an officer spotted Mr Batt riding his motorcycle at more than 100km per hour in a 50km zone but the chase was abandoned within minutes.
A police helicopter located him a short time later and a second pursuit started, continuing despite orders to abandon the chase. Mr Batt crashed his motorcycle soon after.
The report said some officers breached a number of policies, including reaching speeds of more than 120km per hour.
It is critical of a lack of command and control by Northern Communications and a failure to clearly order the pursuit be abandoned. A review of police policies was recommended.
Police say they accept there were shortcomings and are addressing them.