Auckland man Jerrim Toms would still be alive today if police had communicated better, his family says.
It's supported by the Independent Police Conduct Authority report, released last month.
"Police could have contained Mr Toms in a more controlled manner, limited any risk to the public and averting the circumstances that led to his death", it said.
Jerrim was shot dead by police on Easter weekend last year after approaching police with a machete and driving at speed on State Highway 1 north of Auckland.
But frontline police did not know his mother had called them for help earlier that evening because mental health services weren't available after hours.
He was bipolar and had been admitted to hospital five weeks prior, his father Kevin Toms says.
"If the front line people had of known that they would've treated him quite differently."
The IPCA report found the shift commander knew about the 111 call about five minutes before shots were fired and should have relayed that information to the police on the ground.
His toxicology report showed he had been off his medication when he was killed.
"He wasn't frightened of the police unless he was off his medication and then he had a real fear of them," Kevin says.
"The end result wasn't good was it, we ended up with him in a body bag."
The IPCA report heavily criticised the shift commander's role.
"There was poor communication and really a lack of coordination and any planning to bring the matter to an end," IPCA chair Judge Doherty said.
Despite having "plentiful" police resources and options, Jerrim was shot at 12 times by two officers at close range, it said.
Kevin says it was a "sour grape" with the family.
"The dog was standing right next to the officer while he was firing the gun," he says.
"All they had to do was release him and then he would've pulled Jerrim down without any trouble."
Four bullets hit Jerrim but eight bullets missed him.
Investigations also found that at least three of the shots that made contact were from the same officer.
"Two in the heart and one in the back so he was shot in the back as he ran away," Kevin says.
Police say they will not apologise because no fault was found on its part and Jerrim's actions left them with no choice.
The IPCA investigation found the officers were acting in self-defence.
But the Toms family maintains it should never have happened and are not ruling out further action.