Mr Gravatt died aged 22 in July 2009, at the height of the swine flu pandemic. It was just over 15 hours since he began experiencing symptoms such as a fever, headache and extreme pain in his right groin.
At midday a GP had sent him to hospital where a nurse assessed him as triage category 3, which indicated he should see a doctor within 30 minutes. However, it was between an hour and a quarter and an hour and three-quarters before a doctor assessed Mr Gravatt, the coroner said.
In his findings, Mr Shortland is sympathetic over the great difficulty of diagnosing meningococcal disease and the "extreme stress" on the hospital from the pandemic but also criticises aspect's of Mr Gravatt's care.
He agreed with independent reviewer Dr Roger Reynolds, of Middlemore Hospital, who said back-up systems were needed when patients faced too-long waits.
Dr Reynolds believed the real cause of Mr Gravatt's illness - it was at first thought to be influenza - could have been identified earlier if his vital signs had been measured more regularly.
Dr Lance Gravatt, a PhD in chemistry and head of drug company AstraZeneca's New Zealand operation, said it was impossible to say if his son might have lived if correctly diagnosed and treated sooner.
"The thing we find so hard to live with is he wasn't really given a chance. By the time they did get to treating him, he was really in the last few hours of life and everything was packing down ... If they had just taken the normal vital signs [more regularly] from the start, the expert evidence is that they would have been alerted to, maybe not definitely meningococcal disease, but probably sepsis [blood poisoning and organ failure] pretty early on."
The Auckland DHB formally agreed with him through the inquest to promote nationally the use of an early warning scoring system for upping the care of patients with the kind of instability - high temperature, pulse and breathing rate, and low blood pressure - that Mr Gravatt had.
The coroner said the DHB had adopted the system in its adult services and would modify it for use in children's and women's services.
Dr Gravatt said there was a recommendation at the DHB to implement the system following the meningococcal death in 2007.
"Two years later Zac comes along, and they still hadn't implemented [it] from when somebody else had died ... It's about not having systems in place to follow up what you said you would do.
"I really don't accept that it's now four years from that 2007 case and they are still rolling out the early warning scoring system. I think there's a lethargy and ineptness about that."
The DHB, which has apologised for shortcomings in its care of Mr Gravatt, said the introduction was delayed by the resignation of a key employee.
Dr Gravatt said his son's death had taken a terrible toll on him and his family. He became distraught, following another meningococcal death earlier this year, at how long the coroner was taking to issue the agreed recommendations.
"I ended up being admitted by the crisis team as an acute suicide risk. I've spent the last four to five months having weekly psychiatrist and psychologist visits, getting over that ... I think I'm [now] the wellest I've been for a very long time."
What happened
July 8, 2009
* 4am: Zachary Gravatt wakes with fever and extreme pain
* Midday: Sees GP. Thought to be suffering swine flu. Sent by ambulance to Auckland City Hospital.
* 1.43pm: Assessed as mid-level urgency, should be seen by doctor within 30 minutes.
* 2-2.30pm: Nurse assessment.
* 3-3.30pm: First doctor assessment.
* 5-5.15pm: Single, purplish spot found on back.
* 6pm: Transfer to intensive care unit. More spots, now on face. Meningococcal disease suspected.
* 6.40pm: Given antibiotic for meningococcal bacteria.
* 7.15pm: Declared dead.
