"Police showed commendable courage and professionalism on the night of 14 July 2021. They were shot at without warning by a man with an illegally-owned military-style semi-automatic rifle, and only by luck and good training were they spared injury or worse. Their fast actions prevented death or serious injury," said authority chair Judge Colin Doherty.
"But, in other respects, this case showed serious errors by police failing to follow up concerns they had about Mr Buckley, and they should have acted on those concerns on 9 July 2021. Also, by handing firearms back to Mr Buckley that had been previously seized in 2017, Police made a serious error."
The authority said on July 9 last year a report was made to police that Buckley owned illegal firearms and had been threatening to kill or seriously injure his estranged wife's new partner.
When officers attempted to arrest him five days later he fired at them. The officers returned fire, fatally wounding him. The authority deemed the police shooting necessary to protect themselves and others from serious harm.
The report outlined how during a counselling session Buckley's estranged wife revealed her former partner been making threats to kill or seriously injure her new partner and intended to die in an armed confrontation with police.
The counsellor phoned police but was not contacted for a further 66 hours after the calltaker wrongly coded the call as a less urgent matter. The IPCA found that police failed to respond in a timely manner.
The day before Buckley was shot his ex-wife had met with police and told them he was mentally unstable and planning a mass shooting. She showed photographs of military style semi-automatic firearms he owned.
The following day she returned to the police station to complete a statement in which she told police her ex-husband carried a pistol with him at all times in a backpack, and kept a loaded pistol under his pillow in case he was "raided" by the Police. He was also a regular user of illegal and prescription drugs.
While initially dismissing any threat as urgent, this changed when a mutual friend recognised the ex-wife at the police station.
A plan was put in place to arrest Buckley that night involving members of the Armed Offenders Squad.
The report said Buckley pulled up at his home at 10.20pm. When police moved to block him in his driveway and arrest him he started firing on police from inside his vehicle.
Buckley suffered fatal injuries during the firefight.
On whether the police should have returned firearms to Buckley, the report said in December 2017 two firearms were seized and subsequently given back in May 2018 on the basis that they were not semi-automatic firearms.
The report said Buckley had bought two semi-automatic Norinco NHM90 rifles in 2017. One of these was the firearm he later used against officers.
Up until December 2020, it was legal for Buckley to own semi-automatic firearms under a
Category A licence, as long as he did not modify them.
The Firearms Officer directly involved provided two different accounts explaining why the firearms were returned to Buckley.
"By either account, the Authority is critical that the firearms were returned to Mr Buckley and considers this was a serious error," said the IPCA.
The police today said it accepted the findings into the Hamilton man's death.
"This was a challenging and high-stress situation and Mr Buckley's death was an outcome that no one wanted," said Waikato District Commander Superintendent Bruce Bird.
The Emergency Communication Centre employees directly involved were spoken with and the need to seek supervisory advice on how to code an event if unsure had been reinforced.
Police also accepted because it was initially incorrectly coded Hamilton Police staff did not begin making inquiries in the expected time frame.
It also acknowledged the IPCA's findings in relation to the return of the two firearms.
"We have further work to do to understand the full circumstances which led to the return of these firearms," said director operations, arms safety and control, Superintendent Richard Wilson.
"Police does accept the IPCA's overall findings in relation to firearms licensing, and in this instance, we did not act on information available to us about his suitability."