The findings have been released following an inquest which heard evidence that Mr Murtagh had been under the care of several agencies in the months leading up to his death.
Medical professionals, mental health and drug and alcohol counsellors had worked with Mr Murtagh but given his addiction issues, he needed to go through medical detoxification before going into a residential rehabilitation facility.
A bed for the detoxification only became available the day after Mr Murtagh was found unconscious. Mr Robb said if it had been made available earlier, it would have "significantly increased" his chances of being alive today.
"However ... he remained transient, he remained with an untreated addiction and there was no medical detoxification available for him at the hospital until 25 May 2016. By 24 May 2016, it was too late, he was found in the hotel carpark, his addictions having overtaken him, ultimately leading to his death," the finding said.
Mr Robb has made several recommendations and comments including saying the delay in having both medical detoxification and residential rehabilitation beds available was "very troubling" and could "ultimately have a fatal consequence".
He also recommended police "red flag" to relevant agencies anyone who has significant addiction issues.
He also commented Te Utuhina Manaakitanga Trust (a drug and alcohol treatment facility) continued discussions over the use of detoxification beds at Rotorua Hospital, which allowed the trust's assessors to fully participate in allocating the limited bed resources.
The finding said Mr Murtagh was well-known to police and had been arrested 24 times.
On May 24 he was found with a sword down the front of his jeans and had two cans of aerosol spray and cigarette lighter in his clothing.
Two members of the public tried to give him CPR before an ambulance arrived. He was taken to Rotorua Hospital and admitted to ICU but it was determined that he had suffered a severe brain injury following a cardiac arrest.
A decision was made to take him off life-support and he was released to palliative care as there was no chance of him recovering. He died on June 3.
Mr Robb heard evidence during an inquest about how he was under the care of several agencies who were trying to help him but it was challenging given his drug addictions and transient nature as he would often not attend assessments and other appointments.
Mr Robb said the case highlighted that having beds available for both medical detoxification and residential rehabilitation without lengthy waiting lists was "crucial".
"Had he been able to undertake medical detoxification when he was in hospital on 10 and 11 May 2016 and had he then been able to then transition straight into a residential rehabilitation programme, his chances of being alive today would have been significantly increased."
The finding said Mr Murtagh, who was also known as Morris Junior Papariu Paoru-Murtagh, was born in 1995 but was removed from his mother's care when he was 2 and put in the care of the state.
Mr Robb said his life history made "very sad reading".
There were reports of him suffering from abuse, taking magic mushrooms from the age of 7 and starting to huff aerosols from the age of 12.
From 2015 when he was no longer in the care of the state, he returned to live with his mother, but from that time he often lived a transient lifestyle and slept on the streets.