It could be the undoing of South Australia's previously flawless quarantine system — how a security guard working at the state's medi-hotels was allowed to make pizza on the side.
That security guard, who contracted the virus from a hotel worker at Peppers in Adelaide's CBD, set off a further chain of events that saw the coronavirus spread out from its starting point.
Authorities hold fears over the Woodville Pizza shop on Woodville Rd where the guard worked part-time, which is now considered one of the Parafield cluster's hot spots. A close contact of the security guard also caught the virus.
Chief public health officer Nicola Spurrier said the government had received information on Tuesday about a positive case involving a young man who works at the Stamford hotel and they were unclear how he got the virus.
"This person was not a security guard, was not a nurse or police officer but worked in the kitchen and that made us very concerned because we could not work out how on earth that person became infected," she said.
It turned out that person had gone and got a pizza from the Woodville shop.
Initially authorities couldn't link the Stamford man to the security guard, but realised he got the pizza at the same time as another case was working there.
"We had a security guard at the hotel that worked part-time making pizza and we had the person at the Stamford, and we couldn't connect the two, but what we found last night was another person that worked at the pizza bar and we were able to connect those two up because of the time links," Spurrier said.
Spurrier was questioned about why a security guard at a medi-hotel was allowed to also work at a public pizza place, and whether rules would be changed to restrict that.
"We say in medicine, it is very clear with the retrospect, you look back and you think you could have done XYZ, but for me today I am looking forward about what we have to do here and now to get on top of it," she said.
Dr Chris Moy, the president of the South Australian branch of the AMA, said it basically came down to luck that the state uncovered its emerging coronavirus cluster.
Moy said one persistent doctor insisted on giving an unwell elderly woman a coronavirus test.
South Australia had been coronavirus-free for seven months when the doctor pushed to test the woman.
The woman, aged in her 80s, is the mother of the quarantine hotel cleaner, who is believed to have contracted the virus from a surface inside Peppers.
The elderly woman was taken to emergency on Friday night, where she was showing mild symptoms of coronavirus.
Moy said if South Australia did get on top of the outbreak, "a lot will be due to some degree of luck".
"Because of the conscientiousness of a particular doctor who insisted that a patient with minimal symptoms have a test.
"Really to some degree that may make the difference and may mean that we've caught it early and it hasn't got to the Victorian level where it was going on for weeks."
Moy said "by the grace of God" the doctor "stayed committed to that vigilance in a community that hasn't seen any cases for months and then that has actually closed this down".
The doctor's insistence meant South Australia had hopefully caught it quickly and would be able to "control it like a spot fire instead of it turning into a bushfire as it did in Victoria".