That's what Deputy State Coroner Erin Kennedy will have to establish over the course of a two-week inquest into the death of 36-year-old Kamilaroi Dunghutti man Ricky Hampson Jr after being discharged from Dubbo Hospital.

Less than 24 hours after leaving the hospital, Mr Hampson was found dead.

His family believes racial prejudice, his history of incarceration and the fact he was a casual cannabis smoker affected his treatment.

Speaking to the media outside the gates of the Dubbo Court ahead of the first hearing on Monday, February 26, Ricky Hampson Sr - Dougie's father - said his son was remembered by his family as "the life of the party".

He said the father-of-eight's death "devastated" his family.

"For his life to be taken like this is just tragic... he didn't deserve to die, he was an amazing man. We're devastated... this could have been avoided," he said.

Emotions ran high in the courtroom as counsel assisting the coroner Simeon Beckett read out details of Mr Hampson Jr's two-day ordeal after presenting to Dubbo Hospital on August 14, 2021.

The public gallery was filled by Dougie's friends and family, some in t-shirts with Mr Hampson Jr's face and the hashtag "Justice4Dougie", some in t-shirts reading "Justice for Dad".

In the courtroom, an Aboriginal flag is draped over a table. Spread across it are eucalyptus leaves, a St George Dragons beer stubby and a glass #1 Dad tankard. As they filed into the courtroom, members of Mr Hampson Jr's family added photos to the table.

Mr Simmeon told the court that just after 5:00pm, Mr Hampson Jr visited Dubbo Hospital with a highly elevated heart rate after feeling a "popping" and "tearing" sensation in his stomach.

He described his pain level as "10 out of 10" and the nurse who triaged him said he was "writhing with pain" in the waiting room. His heart rate and breathing rate were both high.

A "young and inexperienced" doctor assigned to Mr Hampson Jr's care said it was her impression he had "undifferentiated abdominal pain". She spoke to her supervisor about Mr Hampson Jr's case and under his suggestion she gave Mr Hampson Jr a sedative and fluids.

At about 7:00pm the senior doctor advised Mr Hampson Jr be given fluids, reviewed and discharged and the junior doctor prepared a discharge summary.

However, Mr Hampson Jr's symptoms continued so he was transferred to the short stay unit to stay overnight and given oxycodone to manage his pain.

The next morning, August 15, Mr Hampson Jr's heart rate was still high and his pain was increasing but his other vital signs were within the normal range.

He was not seen by a doctor that morning and was eventually discharged at midday. The nurse who saw him as he left the hospital described him as still being in "obvious discomfort'.

Later asked why he advised the sedative be administered, the senior doctor said it was because he believed Mr Hampson Jr was suffering from cannabinoid hyperemesis syndrome as he had disclosed he had smoked marijuana that morning.

There was no further investigation of the "popping" sensation Mr Hampson Jr reported and he was not given an xray or CT scan.

Later that day Mr Hampson Jr arrived at his relative Marshall Peachey's home in a taxi. Mr Peachey said when Mr Hampson Jr got out of the taxi he "walked over slowly holding his belly."

Mr Peachey stayed with Mr Hampson Jr - who knelt on the floor of the lounge room, hunched over the sofa - until 3:30am. That was the last time he saw Mr Hampson alive.

At about midday on August 16, 2021, children at Mr Peachey's house found Mr Hampson Jr laying on the floor near the lounge. He was unresponsive.

Mr Peachey called an ambulance and began CPR on Mr Hampson Jr. However, when ambulance officers arrived just after 1:00pm, it was clear he had already been dead for some time.

The death was referred to the coroner and an autopsy was performed. Two ulcers were found in his stomach and four litres of fluid was found in his abdominal cavity.

Before the first hearing began, Dougie's family and friends were joined by hospital staff and members of the judiciary for an emotional smoking ceremony outside the courthouse.

Speaking before the court, Stuart Kettle, legal counsel representing the Western NSW Local Health District apologised for the death and offered their condolences to friends and family of Mr Hampson Jr.

"It is hoped that such clinical failings will not be repeated," Mr Kettle said.

Magistrate Kennedy called the ceremony "a very special way to start this very important inquest".

"I want to extend my sincere condolences for this terrible loss you have suffered... in particular to the family I just want to say this is an incredibly difficult task you've been asked to go through," she told the court.

"[Dougie's] never forgotten in this process... we're all here for him."

The inquest into Mr Hampson Jr's death will continue at Dubbo Court on Tuesday, February 27.