Authorities made a litany of errors in their handling of the ill-fated Ruby Princess cruise ship, including NSW Health's "inexplicable" and "unjustifiable" decision to assess the vessel as low risk.
That's one of a raft of findings from a special commission of inquiry into the vessel's arrival in Sydney on 19 March, when numerous contagious people disembarked at Circular Quay, and subsequently spread the virus across Australia and overseas.
After three weeks of hearings, the Special Commission of Inquiry commissioned by the NSW government and led by Bret Walker SC released its findings on Friday.
In the scathing 330-page report, the eminent barrister reserved his harshest criticism for NSW Health.
The report noted that on 10 March the Communicable Diseases Network of Australia amended its guidelines such that everyone on board the ship with newly-defined suspect cases should be tested.
But when a risk assessment was conducted on 18 March, those making decisions did not have the updated definition of a "suspect case".
"This was a serious and material error," the commission found.
The Ruby Princess has been linked to hundreds of cases and more than 20 coronavirus-related deaths across Australia.
The ship - which was low on medical supplies and swabs for COVID-19 tests due to shortages - left Sydney on 8 March for New Zealand and returned 11 days later.
Passengers disembarked before the results of 13 expedited tests showing at least three people had the virus.
The Ruby Princess cruise ship sits off the coast of Sydney, Sunday, April 5, 2020. Source: AAP
The delay in obtaining test results from swabs taken on 19 March was "inexcusable".
"Those swabs should have been tested immediately," Mr Walker said.
"In light of all the information the (NSW Health) Expert Panel had, the decision to assess the risk as 'low risk' - meaning, in effect, 'do nothing' - is as inexplicable as it is unjustifiable."
"It was a serious mistake."
Despite the respiratory symptoms of numerous of those aboard and uncertainty surrounding test results, 2,700 passengers were permitted to disembark as the voyage had been deemed low risk by NSW health authorities.
This is because only 0.94 per cent of passengers presented to the ship's medical centre with flu-like symptoms - not the one per cent required to mandate NSW Health intervention - and none had visited virus-hit countries China, Italy, Iran or South Korea.
Mr Walker said the one per cent threshold had "limited" utility for assessing whether COVID-19 was circulating onboard the ship.
"The more important question was: are there suspect cases of COVID-19 on board the ship?" he said.
"NSW Health should have ensured that cruise ships were aware of the change to the definition of a 'suspect case' for COVID-19 made on 10 March."
The NSW government was also rebuked for then allowing disembarked passengers to immediately onward travel interstate and internationally in breach of the public health order that came into effect two days earlier.
By the time NSW Health corrected the advice on 21 March, Mr Walker said it was "too late" as a considerable number of passengers - including some symptomatic ones - were already in transit.
Those passengers from outside NSW should have been placed into suitable accommodation by the state government, he said.
The Australian Border Force was absolved of any blame in the bungle, with Mr Walker quashing media reports a "basic misreading" of negative flu results by an ABF officer contributed to the decision to let passengers disembark.
"Neither the ABF nor any ABF officers played any part in the mishap," he wrote.
Reflecting on the "sorry episode", Mr Walker said it would be "unhelpful" to make recommendations as they would not amount to much more than "do your job".
"There are no 'systemic' failures to address," he wrote.
"Put simply, despite the best efforts of all, some serious mistakes were made."
NSW Premier Gladys Berejiklian said she would read the dense report over the weekend and respond early next week.
Separate NSW Police and coronial inquiries into the Ruby Princess are ongoing and not expected to report back for at least another month.
