The two-week inquest heard the 21-year-old was suffering from an adverse reaction to a small amount of LSD he had taken with mates the night before to celebrate St Patrick's Day.
He stole two packets of biscuits from a convenience store and some police officers mistakenly believed they were dealing with an armed robber.
Two officers repeatedly drive-stunned Mr Curti, or applied the Taser directly to his bare body at the same time, while others used up to three cans of capsicum spray to subdue him while he lay handcuffed on the ground, the inquest heard.
Most officers said they did not hear Mr Curti wailing, calling out "help" or "what did I do?" as they tried to restrain what many of them described as his "superhuman strength".
The coroner also referred the actions of the officers to the Police Integrity Commission.
She said they had been swept up by "an ungoverned pack mentality, like schoolboys in the Lord of the Flies".
Ms Jerram said taking down Mr Curti involved "a frenzy of officers" most of whom were inexperienced and some "behaving out of control".
She concluded there was no specific cause of death but she ruled Mr Curti died in the course of being restrained by members of the NSW Police Force.
The coroner said Mr Curti was a fit and healthy young man whose intake of LSD that day had made him paranoid and fearful, but he posed no threat to anyone else and perhaps not even to himself.
Police should consider prohibiting the use of tasers in "drive-stun" mode, the coroner said, and also ensure officers were fully trained in avoiding "positional asphyxia" when restraining people.
Ms Jerram said the case had been extremely distressing for the family of Mr Curti, who was a much loved young man.
She praised the two police investigators involved in the case.
Outside the inquest, Mr Curti's brother-in-law Michael Reynolds read a statement saying the family was still in shock and full of sadness and anger.
"The coroner has highlighted how excessive, reckless and thuggish some of the police officers were on that evening," Mr Reynolds said.
The family supported the coroner's recommendation that five officers face disciplinary action, he said.
But the family and its lawyers believed that criminal charges should also be laid and has made a formal request to police to pursue such charges.
"Whilst nothing will ever bring Roberto back, we continue to push for those responsible to face the consequences for their appalling behaviour on that night," Mr Reynolds said.
"By doing this we hope to prevent other young people and their families from suffering the way that we have."
- AAP
