Murders, suicides, medical negligence, and deaths that should trigger public health warnings could be missed if proposed law changes go ahead, experts say.

The Coroners Amendment Bill aims to reduce the time it takes for certain types of cases to move through the coronial process, says Minister for Courts Aupito William Sio.

“By making these targeted changes to the Coroners Act 2006, we will create more efficient processes to clear the backlog, and help many families and whānau who are experiencing unnecessary distress from the delays.”

Four amendments include establishing associate coroners to perform most functions of a coroner except inquests, giving coroners powers to decide not to hold an inquest, and allowing written findings to be issued with the cause of death only if the broader circumstances are not considered to be of public interest.

However, it’s the proposal to allow the cause of death to be recorded as “unascertained natural causes”, with no need for an autopsy or further investigation, that has forensic pathologists worried.

Dr Simon Stables said in the early stages of a duty coroner’s investigation, information including medical records and statements from family can be missing. Photo / Jason Oxenham

Northern Forensic Pathology Service clinical director Dr Simon Stables told the justice select committee in October the amendment was “flawed” and would not make any difference to the workflow of coroners.

“It is true some deaths cannot be determined, in terms of cause of death and that’s even after a full post-mortem. Those deaths are well less than 5 per cent of all deaths,” Stables said.

“To institute a policy or especially legislation that allows a non-medical person - that is, a coroner - to determine the cause of death without adequate death investigation, without a post-mortem, just because on the surface it seems as if the person died of natural causes, I think is a very slippery slope down. This is a dangerous practice.”

In his 27 years of experience as a forensic pathologist, Stables said many deaths that appeared to be from natural causes turned out to be from trauma or drug toxicity, either suicide or accidental.

“You cannot determine that, at that very limited investigation at that duty coroner stage. If we’re going to write deaths off then, I think we’re not serving the public, we’re not serving families and we’re not serving whānau.”

Police are called to sudden deaths and investigate on behalf of the coroner if the coroner accepts jurisdiction.

A duty coroner is informed of the death if it is unexpected, violent, or suspicious, or happens in official care or custody.

A coroner can determine a death “on the papers” or call an inquest, making recommendations to help reduce the chances of similar deaths in the future.

The huge backlog in the system means some families wait years for answers over their loved one’s death.

Stables said it was not just the cause of death, but the manner of death that was important, and a limited investigation could miss vital clues that point to this.

“I’m concerned we are going to miss cases at that very early stage if we don’t take an interest in them.”

Philip Nisbet's murder was originally deemed a suicide by police until sister Lee-Anne Cartier uncovered evidence that prompted a coroner to find doubt in that cause of death. Photo / Supplied

The New Zealand Law Society said in a letter to the Ministry of Justice last year about the amendments that there was a risk in issuing a death certificate citing natural causes too hastily, because the early closure of the case could potentially thwart the opportunity to gather crucial evidence, such as bodily samples.

In its recommendations to the justice select committee, it said the Bill should provide that a coroner can only record the cause of death as unascertained natural causes after obtaining a certificate or letter from a pathologist.

It also wanted the Bill to require coroners to have regard for the desires of wider family members when deciding whether to open and conduct an inquiry into a death.

In its letter last November the Law Society highlighted the murder of Christchurch truck driver Phil Nisbet who was poisoned by his wife Helen Milner, but who police believed died by suicide after Milner produced a fake suicide note.

It was only when Nisbet’s sister Lee-Anne Cartier challenged the evidence over the cause of death supplied by Milner, who was the designated next of kin, that the coroner was able to find enough doubt for police to open an investigation.

Milner was charged and eventually convicted of her second husband’s murder.

Forensic Pathology South Island clinical director Dr Leslie Anderson said coroners had no medical training and therefore should not alone be determining which deaths were from natural causes.

“Having them make those decisions without medical advice would continue to result in unnecessary cases being accepted into jurisdiction and could also result in subtle accidents, suicides and even homicides being missed and released as natural causes.”

Anderson said listing a death as “unascertained natural causes” was an inappropriate and unnecessary approach to death certification.

“It compromises death statistics, it undermines the integrity of the death investigation system, and it misleadingly communicates that an investigation has been done.”

Former Rotorua Coroner Wallace Bain during an inquest in 2019. Photo / Stephen Parker

Former coroner Wallace Bain said he signed off some deaths as “unascertained” during his 28 years as a coroner.

He said many Māori families did not want a post-mortem because of the interference with the body and the time it took.

Bain said he always explained the advantages of having post-mortem results, particularly if there was a genetic condition, and in the early 1990s he directed urgent autopsies to allow a body to be returned to the marae as quickly as possible.

Inquest ordered 11 years after death

The whistleblower doctor who campaigned for more than a decade for an inquest into the death of a Waikato Hospital patient believes ruling a death as natural causes too early could lead to medical mistakes being missed.

“It would be a step too far given there is already enough room in the system for a death like Carmen Walker’s to be missed,” Adam Greenbaum said.

Last year the Solicitor-General ordered a new inquiry into the 2010 death of 78-year-old Walker following cancer treatment at Waikato Hospital, after the pathologist who conducted the autopsy changed his conclusion on the cause of her death.

Following an inquiry Coroner Alexander Ho ordered an inquest, expected to take place next year.

The death of Carmen Walker, who died after undergoing a palliative melanoma treatment at Waikato Hospital, will be investigated at an inquest. Photo / Stuart Munro

Walker had Stage 4 melanoma but was otherwise well and active when she opted for a palliative melanoma treatment called an isolated limb infusion (ILI), where high doses of chemotherapy were washed through the lower leg to treat cancer that had spread from her right ankle.

The treatment was supposed to extend the Whanganui woman’s life but instead she died in the intensive care unit that night.

Pathologist Dr Ian Beer initially concluded Walker had died of cardigenic shock, where the heart suddenly can’t pump enough blood around the body, often caused by a severe heart attack.

Former Coroner Gordon Matenga based his April 2011 findings made “on the papers” for Walker’s death on Beer’s autopsy and the surgeon’s notes, listing cardiogenic shock as the cause of death.

But last May Beer took the unusual step of writing to then Chief Coroner, Judge Deborah Marshall, telling her he wanted to change his finding to hypovolaemic shock due to blood loss and asked that a coronial inquest be opened.

Hypovolaemic shock was the cause concluded by an expert in the Health and Disability Commissioner’s 2013 investigation but Beer only discovered that last year.

Greenbaum, who was observing the procedure, alleged systemic failures at the then Waikato District Health Board contributed to Walker’s death and were “covered up”.

Adam Greenbaum spent a decade trying to have a Waikato Hospital patient's death scrutinised by coronial inquest. Photo / Alan Gibson

He believed Walker’s death was avoidable and maintained the failings needed to be recognised so that the mistakes could be learned from, and to give closure to Walker’s family.

The plastic surgeon said Walker’s death in hospital care was a mandatory coronial referral “and yet it took 10 years of campaigning to get her the inquest that she most definitely needed”.

In a submission to the health select committee after he petitioned Parliament for a full inquiry, Greenbaum has suggested medical examiners be set up in New Zealand to look at every hospital death as is the case in England.

Greenbaum said the doctors would be senior specialists with a background in hospital medicine who give a portion of their time to inquire into each death “as a safety net”, liaising with the coroner and families.

“I firmly believe that if this were instituted in New Zealand, none of the deaths like that of Carmen Walker could ever be missed.”

- Natalie Akoorie, Open Justice