Police kept chasing gunman Stephen McDonald because they feared he could go into a house and take hostages, a court has heard.

Yesterday, Inspector Willy Taylor contested criticism from a decorated former policeman at the inquest in Auckland into the death of 17-year-old Halatau Naitoko.

Neville Matthews, a retired superintendent, had earlier claimed that police should have called off their pursuit of McDonald - which ended with an officer mistakenly shooting Mr Naitoko on the Northwestern Motorway in January last year.

Mr Taylor said McDonald was an armed offender who had pointed his gun at police, shot at the police helicopter and taken cars at gunpoint.

"At the back of my mind there was a scenario where he goes into a house, he takes his firearm and he takes hostages," the inspector said.

He said he had overseen 300 pursuits by January last year.

"The ending of the pursuit had tragic consequences that were totally unforeseen to everyone involved."

Mr Taylor believed he had complied with police pursuit policy, which was not black and white but had "room for legitimate manoeuvres".

"I still consider that I acted within the bounds of the policy but accept that others may have a different view."

Mr Matthews, a police officer for 37 years, carried out a review at the request of coroner Gordon Matenga.

Yesterday, he told the inquest the pursuit was not run according to policy.

Mr Matthews said McDonald's P-fuelled driving was erratic and he could have been followed from the air by the police helicopter.

He said officers could have "marshalled" resources, then arrested McDonald in a way that would not have put the public at risk.

The retired superintendent said that throughout the chase, McDonald had been in control, and stopping the pursuit would not have changed that.

"There was no option but to abandon the pursuit," Mr Matthews said.

He said Mr Taylor was only aware of 10 cars chasing McDonald. There were in fact 20 vehicles in the pursuit, which slowed armed offenders squad members getting to the scene.

The AOS had been called but only five staff responded, in two vehicles.

The squad planned to do a "non-compliance stop" involving three squad cars and nine staff manoeuvring the offender's car off the road.

"Anything of that nature would have required a containment of McDonald and that would have required more staff."

Mr Matthews said the squad had no formal debrief, which would have been "extremely important in bringing out the issues - both good and bad".

McDonald was sentenced to 13 years in jail on 23 charges relating to his P-fuelled rampage.

The inquest continues today when Superintendent Paula Rose, the national road policing manager, is expected to give evidence.