WorkSafe did not prosecute the Transport Agency over a roadworker being killed despite an expert telling it to.
The only company or agency which was charged, Fulton Hogan, said others should have been beside it in court.
Joji Bilo, 25, was killed by a runaway truck in Ngauranga Gorge in early 2019.
The vehicle's handbrake had failed.
Fulton Hogan pleaded guilty to one health and safety charge laid by WorkSafe.
Managing director Cos Bruyn said they accepted the sentence and had supported the family.
"They're the ones who are going to carry that loss for the rest of their lives and this was truly an avoidable accident," Bruyn told RNZ.
Following a similar fatality in 2010, the Transport Agency Waka Kotahi issued years of safety alerts about the type of handbrake that could be dislodged simply by shutting a truck door.
Fulton Hogan banned them in 2012, although the message did not get through to the subcontractor at the Ngauranga site.
Waka Kotahi finally outlawed the brakes in 2021, two years after Joji Bilo's death.
Bruyn described that as "very tardy".
"There's at least two clear fatalities that directly link to the fate of this handbrake.
"The risks could have been removed from our sites and from New Zealand public roads, completely, if they had stepped in."
The gorge accident could have happened anywhere, say, outside a school with "even more tragic consequences", he added.
"How many people have to pay the price before bureaucrats get their A into G?"
'Action should have been taken against other parties' - Fulton Hogan boss
He revealed that an expert report that WorkSafe commissioned said others should have faced charges, too.
"It clearly highlights that, you know, action should have been taken against other parties.
"They didn't do it within that timeframe, so therefore, it left Fulton Hogan being the last man standing, so to speak," Bruyn said.
"There should have been other people standing alongside us when that judgement was happening."
WorkSafe issued a statement acknowledging the report's advice.
"WorkSafe's expert considered that other parties should have been charged, including NZTA and VTNZ," it said.
"Despite its findings, prosecutions were not initiated against NZTA or VTNZ as WorkSafe's view was that the requirements of the Solicitor-General's prosecution guidelines were not met."
The watchdog is the frontline regulator when it comes to work-related road crashes.
VTNZ inspectors had checked the truck three days before Bilo died, court documents said.
The judge noted that police said the inspectors should have spotted faults with the handbrake and taken the truck off the road for "urgent maintenance".
"The Police's Fatal Crash Report subsequently concluded that VTNZ staff should have been aware of the many safety concerns and alerts previously issued relating to the Sanwa Seiki park brake," the ruling said.
VTNZ told RNZ WorkSafe found it inspected the truck in line with requirements, and it had no part in the court proceedings.
WorkSafe has a 12-month window after a death to lay charges.
It did not get the Ngauranga expert report done until 18 months after that window closed.
"The independent expert report, dated 14 October 2021, was carried out as part of our preparation for trial," it told RNZ.
Cos Bruyn questioned why.
"They should have sought professional advice, right from an early stage to make sure they've captured the right people."
In late 2021, WorkSafe dropped charges against a subcontractor, a truck company and a director, and amended what Fulton Hogan faced to a single charge.
Joji Bilo's mother-in-law Una Kama told RNZ after a court hearing last year that the family was grateful Fulton Hogan pleaded guilty but had wanted others to face the court.
"The truck owners, and maybe the driver also, but we understood there wasn't enough evidence to make the charges stick," she said.
The driver was injured by his runaway truck. The court heard it was parked facing downhill without its wheels turned to the kerb and without being put in reverse gear.
Bruyn questioned if all the country's 1000 trucks with the dodgy Sanwa Seiki handbrakes had actually been taken off the road by now, and also questioned the value of the Certificate of Fitness check (like a car WOF, but every six months) that didn't pick up the fault.
"So you should, as an employer, or anyone, be able to rely on a modern vehicle who's just had a Certificate of Fitness being fit for purpose.
"So once again, it leads us back to [that] paperwork controls, ultimately, are not good enough."
VTNZ said its "thoughts remain with Joji Bilo's family after this tragedy".
"The ban on this brake component was issued by Waka Kotahi in 2021, and VTNZ supports the efforts to strengthen these safety regulations," chief executive Greg O'Connor said in a statement.
Bruyn and several other Fulton Hogan executives apologised to the Bilo family members in person at a court hearing last September.
Waka Kotahi has been approached for comment.