The Independent Police Conduct Authority has found officers repeatedly disobeyed orders and breached policy during an early morning pursuit in which one officer was seriously injured.
The authority on Friday released its report into the early morning chase on Auckland's North Shore in March last year.
An officer, called Officer A in the report, was twice ordered to abandon the chase, but did not acknowledge or comply with the first order.
Road spikes were used at an intersection but the evading driver who had taken methamphetamine ran over those, swerved toward two other officers who laid them and hit one of them, Officer C, who was not wearing a reflective jacket.
Officer C suffered a mild brain injury, cuts and bruises.
The IPCA says Officer C broke two rules - his choice of location did not provide cover and he was not wearing a reflective jacket.
Officer C told the authority they had never laid spikes before, other than in practice.
About half a minute after the officer was hit, Officer A was again ordered to abandon the pursuit - and again did not obey the order.
The car ended up losing a wheel but the driver continued, and crashed into the estuary off the Beach Haven wharf.
The IPCA says the injured officer suffered serious harm because of uncoordinated actions, and rules were disregarded.
It says the officer's failure to abandon the pursuit was unjustified, and the pursuit controller was not firmly in command.
Police admit actions uncoordinated
In a written statement, police acknowledge the officers' actions were uncoordinated but say it was the driver who ultimately caused the chain of events.
Superintendent Bill Searle says several of the recommendations are being worked on, including internal performance measures for some of the officers involved. Police also want further training for the use of road spikes.
The injured officer has since recovered and returned to full duties.
Three officers will be given refresher training and all those involved will have their performance measures scrutinised.
The driver they were chasing had more than 50 earlier convictions and was jailed for seven years.
Officers cleared over triple fatal Christchurch pursuit
A second Independent Police Conduct Authority report says two officers did nothing wrong in their pursuit of a car that crashed in Christchurch in July this year, killing three people.
It says the officers complied with law and policy when their patrol car pursued a vehicle, carrying five people, for about 30 seconds.
The Mitsubishi Lancer crashed into a concrete pole, killing the front seat passenger. The driver and another passenger died later in hospital.
The car's rear tyres had little or no tread and the driver was over the blood alcohol limit.