At first, his parents, Kristine and Andre Scott, suspected two swollen lumps in his mouth – sites for two emerging teeth – were the problem. But then his temperature rose and he started to vomit. They decided to take him to Geelong Hospital, the closest to where they live. As relatively new parents, it seemed the safest thing to do. But as it turned out, Leroy was not safe. He died from a bacterial infection three days later.

Earlier this year, Coroner Jacinta Heffey ruled that Leroy's tragic, unexpected death could have been prevented if staff at Geelong Hospital had detected the bacteria ravaging his body sooner, and treated it with antibiotics earlier.

The Scotts are now considering legal action against the hospital with lawyers at Maurice Blackburn. But more than any sort of compensation, they want people to understand how a series of delays, oversights and "one per centers" conspired against them to steal their beloved son. They also hope health professionals working in busy hospitals will read their story and listen to parents when they tell them their child is deteriorating.

In many ways, Leroy's demise was a perfect storm. Life threatening bacterial infections are rare in children, especially children who are otherwise healthy, but they do happen and doctors know they can be catastrophic.

The timing of Leroy's illness was also unfortunate. When Kristine and Andre realised their son needed urgent medical attention, it was a Saturday night on the Anzac Day long weekend of 2011. Long weekends have been linked to higher death rates for patients in hospitals overseas, mainly because of a lack of "downstream" staff, such as those processing tests for medical teams.

But the Scotts had no choice. Leroy was vomiting and had a fever, and a GP had told them earlier that day to seek medical help if his condition deteriorated.

When the Scotts arrived at Geelong Hospital's emergency department around 9:15pm, it was busy with the predictable sort of human traffic seen on Saturday nights. In their first few hours in the waiting room, Leroy continued to vomit and every part of his 15-kilogram body was hot. The inquest heard he was given some paracetamol, but waited eight hours to see a doctor.

At 5am on Sunday, a paediatric registrar examined Leroy and suspected an ear infection. An attempt to put an intravenous cannula into his arm failed but staff still managed to take some blood to run a range of tests, including for bacteria to see if antibiotics may be required.

Geelong Hospital's laboratory, St John of God Pathology, received Leroy's blood at 5:50am. It took more than four hours for a scientist to put it in an incubator at 10:18am.

While doctors in the children's ward waited for test results to see what was causing Leroy's illness, the inquest heard the treatment plan was fluids, pain relief and monitoring. While antibiotics could be given at any time in case of a bacterial infection, they would be useless for a virus and giving them would involve inserting an intravenous line into Leroy's arm – a potentially traumatic intervention. They opted to wait for his blood test results.

On that Sunday, paediatrician Peter Vuillermin noted that Leroy had an elevated "C-reactive protein" reading (a sign of inflammation and possible marker of a bacterial infection). He noted that while a "serious bacterial infection [was] still possible", he believed a virus was more likely.

About 7pm that night, Leroy's temperature spiked at 40.2 degrees. He was still miserable, but staff thought he was responding well to pain killer medications and Dr Vuillermin noted on his medical record that he "looks improved".

The next morning, there was a significant development. About 10am on Monday the 25th April, the head of Geelong Hospital's infectious diseases department, Dr Eugene Athan, discovered Leroy's blood test included bacteria resembling staphylococcus – a pathogen that kills one in 10 people it infects, even when they are promptly treated with antibiotics.

In her finding, Coroner Heffey said Dr Athan relayed the positive result to the nurse in charge of the children's ward and offered to speak to the paediatric registrar on duty Dr Eta Raicebe who was working with consultant paediatrician David Fuller to manage Leroy's care.

But they never spoke. Instead, Dr Athan said that while he was talking to the nurse on the children's ward, he got the impression that the registrar was nearby and had informed the nurse that the treating team were content with Leroy's status and wanted to wait for a further "culture confirmation" test before they began administering antibiotics. The message was passed on to Dr Athan.

The inquest heard that this second test was discussed because it would help doctors more accurately determine whether the bacteria was a contaminant – that is, bacteria sitting on Leroy's skin that got into his blood sample when the sample was drawn. This contamination of samples happens a lot because staphylococcus often sits on people's skin.

A delay in the lab followed. Coroner Heffey said the confirmation test was not set up by St John of God pathology staff until 2pm. On a normal working day, the test would involve a reading at two hours, four hours and 24 hours, but it was Anzac Day. While the first of these three readings was possible before staff left the lab at 5:30pm that day, for unknown reasons they did not get to it.

By Monday afternoon, Kristine and Andre were becoming increasingly concerned about their boy who had mostly clung to them since they arrived at the hospital two days earlier. Exhausted but anxious to ensure Leroy was OK, they had been taking turns to rock him in their arms, and Kristine had been trying to breastfeed him with little success. He was not drinking and earlier that day, he had woken with an "angry" looking rash.

"He had all these little lumps under his skin," Kristine told the inquest.

Around this time, the Scotts say they started to ask more questions. They wanted the nursing staff and registrar to examine Leroy again. Initially the staff were responsive – Dr Raicebe told the inquest that she looked at Leroy's rash and said it was consistent with a viral infection, not a bacterial infection. But by the early evening, Andre, Kristine, and her mother Barbara, were not reassured and felt Leroy's condition warranted further investigation.

Some time before 7pm, Barbara and Andre both asked nurses if the on-call consultant, Dr Fuller, could review Leroy again. They were told he was unavailable.

Dissatisfied, Barbara, a nurse who had worked at Geelong Hospital, called her sister and asked her to phone a manager on duty at the hospital whom she knew.

A short time later, Dr Fuller was called. As he prepared to review Leroy around 8.20pm that Sunday night, Dr Fuller told the inquest that he contacted Dr Raicebe to get an update on the laboratory testing. He says she told him that the laboratory would not be able to provide results that day.

But Dr Raicebe's evidence was different. She told the court she had not heard anything back from the laboratory and had assumed, therefore, that the test had shown the "staph" was a contaminant.

When Dr Fuller arrived to see Leroy, the Scotts felt like things were moving but there was little progress with a confirmed diagnosis regarding the possible staph infection. Dr Fuller noted Leroy was wheezing, so organised a chest and abdominal X-ray and prescribed Ventolin. The X-ray showed patchy changes and Dr Fuller concluded he had viral pneumonia that did not respond to Ventolin.

Around this time, Leroy's naso-gastric tube was dislodged, prompting discussion among staff about whether it should stay in or out. It was removed, leaving no alternative route to hydrate the sick boy.

After Dr Fuller left, Kristine and Andre saw more causes for alarm. Leroy was still barely drinking and his nappies remained dry throughout the night. They told the inquest that they kept reporting their concerns to nurses, but felt their words were falling on deaf ears.

The Scotts say they were so frightened by Leroy's condition that at one point during that night, they discussed carrying their son out of the hospital to their car and embarking on the hour-long drive to the Royal Children's Hospital in Melbourne. But they decided it was too risky. "What if he had a seizure on the way?" Kristine thought.

"I felt like I was seeing one baby and the staff were seeing another," she told the inquest. "Around 3am, I felt desperate so I called my mother and asked her to come in."

A short time later, a nurse came in to give Leroy codeine, but it did not relieve his distress. Around 3am, Dr Raicebe reviewed Leroy again, but did not see any reason to change his treatment plan. She noted he had passed some urine and that his vital signs were in the upper range of normal.

Around this time, Kristine said Leroy's legs and arms were so cold, she wrapped him inside her clothing and walked him up and down the corridor until her mother arrived. When Barbara walked in, she was shocked by her grandson's appearance. Barbara called her sister Judy to come in and help them negotiate his care.

At 5am, Dr Raiciebe also noticed a drastic change. Leroy's body was now coated in large raised pink and purple lesions. It was a purpuric rash, the kind that accompanies a serious bacterial infection. The nurses were now noting whimpering cries and grunts from Leroy – sounds he had not been making before.

Dr Raicebe phoned Dr Fuller at 5:17am and they agreed Leroy needed intravenous antibiotics. While she was organising this, the inquest heard she called Dr Fuller again at 6:11am to say the Scott's wanted him to come in. There was a lot going on. Dr Raicebe was being called to the maternity ward for a birth she was responsible for while she was also trying to arrange antibiotics for Leroy. When Dr Fuller arrived, she asked him to take over.

As Dr Fuller was assuming control, Coroner Heffey said Leroy's heart rate surged to 200 beats per minute. He was in shock. A sudden drop in his blood pressure meant there was not enough blood circulating to his organs.

Realising the urgency of his condition, Dr Fuller called for a transfer to the Royal Children's Hospital to be arranged. An air ambulance was dispatched but foggy weather prevented it from landing, so a road ambulance was sent instead.

As panic welled in Andre and Kristine, Dr Fuller made several calls to Geelong Hospital's intensive care unit, requesting they prepare for Leroy who needed a tube in his airway to assist with resuscitation.

"I knew at that point that things were bad, and began to cry," Andre recalls.

Kristine continued to recite stories to Leroy to keep herself and him as calm as possible.

"At some point, he was given morphine and then everything started to change. His colour completely faded and he was no longer responsive," Kristine remembers.

Leroy and his family were moved to the intensive care unit. Andre recalls a female paediatrician Dr Christine Sanderson trying to reassure them that "everything would be fine".

But it wasn't. And they knew it.

At 10:12am, Leroy went into cardiac arrest. A large team of doctors tried their best to resuscitate him, but they soon realised his small frame could not take any more. The toddler died at 10:58am.

During that last desperate hour of Leroy's life, Coroner Heffey said the test that had been ordered to confirm a bacterial infection in his blood sample was reported to Geelong Hospital at 10:18am. It was positive. He had a staphylococcus aureus​ infection in his blood. It was not a contaminant. At 10:42am, the paediatric emergency team dispatched to take Leroy to the RCH arrived. It was too late.

When Kristine realised her boy had died, her first instinct was to remove the leads from his precious body so she could take him home.

"I went over to the bed and picked up my baby," she remembers. Staff tried to convince her to stay. But she refused and walked out of the hospital with him in her arms.

"Once we got down to the street, I could no longer feel my legs and sat down on the ground with Leroy ... I noticed Verelle, one of the ICU nurses, sitting nearby on the edge of the footpath smoking a cigarette and crying."

Andre escorted Kristine into their car and they drove Leroy home.

After investigating Leroy's death, Coroner Heffey said expert evidence suggested Leroy was very likely to have survived if he was given antibiotics on the day before he died. She said this was the "saddest aspect of his treatment".

"In most hospital deaths that become coronial investigations, the outcome of adopting a different clinical course is rarely so clear cut," she said.

But Coroner Heffey said the clinical decision making leading up to his death was not equally clear cut. She did not hold any of the doctors who cared for Leroy responsible for his death.

At the beginning of the inquest, Dr Fuller conceded that he should have given Leroy antibiotics when he saw him on the Monday night before he died, even without a confirmed result from the laboratory. But he said the clinical picture during that day suggested Leroy had a viral illness and would be among the estimated 90 per cent of people who return a contaminant result, ruling out a true bacterial infection.

"I'm sorry that we didn't pick up the seriousness of his illness until it was too late. I'm sorry that I didn't start antibiotics earlier than I did. And I'm sorry that much of your time in hospital with Leroy was filled with anxiety about his condition and frustration at not having your concerns heard," he told the court.

Given this concession, Coroner Heffey focused on whether Dr Fuller should have conducted more investigations and/or commenced antibiotics following an 11:30am review of Leroy on Monday April 25 – the day before he died.

Coroner Heffey said although there were delays in the laboratory's processing of tests for Leroy, after his doctors were told about the initial positive result for staph on Monday morning, both Dr Raicebe and Dr Fuller could have chased up the results of the confirmatory tests they had ordered to try and rule out a contaminant on the Monday afternoon.

Furthermore, she said there was an after-hours phone number for laboratory staff to get urgent results.

During the inquest, Dr Raicebe conceded that she should have followed up the results but was busy and forgot to do so. Dr Fuller said that he did not know what time the lab closed but expected that if there was going to be a result that afternoon, someone would have communicated that result to him.

There were also other things that could have been done on Monday to speed up Leroy's diagnosis and treatment, Coroner Heffey said. This included taking more blood from Leroy on Monday morning to repeat the CRP test because an updated result would have been useful to build a picture of a bacterial infection. The doctors also could have asked the lab how long it took for the initial positive staph result to be revealed – more information that helps build a case for or against a contaminant.

"I consider that this would have been best practice in the circumstances, even though Dr Fuller thought the results [of the confirmation test for bacteria] would be available later that [Monday] afternoon," Coroner Heffey said in her finding.

While Coroner Heffey pointed to several omissions in Leroy's care, and some expert witnesses said there were mounting signs to suggest a bacterial infection, she said Leroy's presentation was not typical of a child with a bacterial infection, making it difficult for her to conclude how much Dr Fuller's actions were a departure from acceptable standards in his profession.

"There is no evidence to suggest that he [Dr Fuller] did not consider that he was acting in Leroy's best interests," she said.

Since Leroy's death, Coroner Heffey said Geelong Hospital had made a number of changes to try to prevent a death in similar circumstances. The hospital now tells staff that parental concern should factor into decisions about calling "medical emergency teams" to provide a fresh set of eyes on patients who are deteriorating.

The hospital has also formalised a process by which parents and carers can escalate their concerns if they detect worrying changes in their loved one. There have also been improvements to its handover guidelines and observation charts to make them more sensitive to family members' input.

St John of God Pathology have also made changes after Leroy's death. All tests designed to confirm a bacterial result is not a contaminant must be reviewed by staff before the lab closes, regardless of when the test started.

As the Scott's recently marked the fourth anniversary of Leroy's death, they tried to focus on their happy memories of a cherubic, thriving boy who loved gardening, being read to and dancing to Johnny Cash in their living room.

But they remain angry about the way in which he died and they feel let down by a health system that was meant to be world class. A system they thought they could trust.

While no individuals have been held accountable for Leroy's death, they hope that will not dull the lessons required to prevent another child dying in similar circumstances.

"Leroy's suffering and death was avoidable and the heartbreak and longing endured by all those who loved him, unnecessary," Kristine said.

A spokeswoman for Geelong Hospital declined to comment due to the Scott's legal action.