Westacott now admits the timing of the Grand Prix was like a "perfect storm".
"If you look at the landscape five days earlier, there were 86,000 people going to a cricket game at the MCG," he said in a recent podcast.
"We were right on the cusp with the Grand Prix, and then a week later people have got the ability to cancel events into the future. The timing was probably the perfect storm, but it was anything but perfect for all of the teams, whether it's Supercars or TCR or the staff at the AGPC, our sponsors and the fans that were outside the gate when lots of decisions were being made."
Westacott says the FIA, the teams, F1 and the Victorian government, were all involved in the decision-making "but things changed overnight".
"We certainly knew that there were the views of the teams, but those are things that need to be ratified and finalised via discussions with the FIA and Jean Todt and Formula 1 and Chase Carey," he added. "And one of the things was Chase Carey was on a plane from Vietnam at the particular time this was all happening."
Carey had gone to Vietnam to check on the likelihood of that inaugural event proceeding, given the Chinese GP had been cancelled and the Bahrain GP was to be a crowd-free event at that stage. Since then, eight grands prix have been cancelled or postponed, including Vietnam.
Drivers have been talking to the media, who have little else to report, about what transpired after it was known a McLaren mechanic had coronavirus and the McLaren team had withdrawn from the event.
Haas driver Romain Grosjean says he received a text early Friday from Vettel.
"Thursday to Friday I didn't sleep very well. At 3am I was WhatsApp-ing with Sebastian Vettel." he said. "I was like 'where are you, why are you awake?" and he's like 'I'm going to the airport'. He was like 'its cancelled, it's not happening'. I said I haven't heard anything official so I stay around.
"He said 'my team has told me that I'm free to go so I'm gone'. So like, 3, 4am on Friday morning in Melbourne time that's when I knew things were going to not look right."
Grosjean says the "bigger picture going forward is much more important than going racing, even though it feels very strange to be at home at this time of the year".
Grosjean's story is telling, because it means Ferrari knew the event was going to be cancelled after the meeting with the FIA, FOM and the AGPC, which reportedly finished around 2am, as an hour later Vettel was telling Grosjean he was catching a flight home.
Kimi Raikkonen and Max Verstappen also left early Friday morning. Together with McLaren drivers Carlos Sainz and Lando Norris, that meant five drivers wouldn't be taking part in the GP. The cancellation decision could have been made by then so the frustrated fans would have awoken to that news and not left for the track.
From his home in Perth, Australian Renault driver Daniel Ricciardo has had time to reflect on what happened in Melbourne.
"I definitely had some tunnel vision because Melbourne is such a busy and chaotic race," he told the Age. "I hadn't given too much thought to the whole corona situation, but deep down I had some concerns. We were definitely playing with fire.
"You start replaying every interaction you had, who you spoke to, where you were. It was easy to get paranoid. Even a few weeks earlier we were all in Barcelona at testing, there were no restrictions, typically everyone has a cold at that time of the year in Europe ... your mind definitely wanders."
"Once we got closer to the race and when you saw what was going on with other sports like the NBA, I was definitely thinking 'no, we absolutely shouldn't be doing this'."
He did not say it could all have been better managed, rather he just added: "I'd be naive if I said I knew everything that was going on because so few of us did."
His former Red Bull boss, Christian Horner, says the decision made in Melbourne was a really difficult one "because it was such a moving target".
"If the guy had tested positive before, then we wouldn't have come and then obviously we'd have all been saved a trip. It's a shame, but at the end of the day, you have to put the health and wellbeing of the fans, the spectators, the team members and the public first."
The organisers of the Azerbaijan GP, scheduled for Baku on June 7, decided to postpone two months before then to avoid what happened in Melbourne.
"I really want to say that I think no promoter should be in a situation that the Australian promoters have been in, and I really feel sorry for Andy Westacott and his team," the City Circuit's executive director Arif Rahimov says.
"I think it's absolutely terrible what he had to go through, and cancelling the event last-minute is a disaster for the promoter. This really is something that I think every promoter wants to avoid right now. We made the call before we built any of the track. We really wanted to make sure we don't incur any unnecessary expenses."
The first scheduled race is now the Canadian GP in Montreal from June 12-14, but given no work can be done to set-up the circuit on a man-made island in the St Lawrence seaway, it seems most likely the race will be postponed. A rescheduled race would have to occur before mid-October, which is when the Canadian winter starts.
Ferrari boss Mattia Binotto says the teams will consider a revised calendar. "We have decided to give total freedom to the FIA to set up a timetable to get back to running as soon as possible, our availability is there," Binotto says.
But former F1 boss, Bernie Ecclestone, says the only safe thing to do is cancel the whole season.
"Today, what would I do?" I think I'd have to say we're going to close down talk of having any races this year," Ecclestone told Reuters.
He has also questioned whether F1 owner's Liberty Media will bankroll a race if it doesn't go ahead.
"If it doesn't go ahead because things get worse they will cover all of the expenses laid out, and, if it does go ahead, they will make up whatever losses the promoter might have incurred for moving their slot. But I think it will be difficult for Liberty to jump up and say they are going to do it. It depends how much."
He says cancelling the season is "the only thing you could do safely for everybody so nobody starts making silly arrangements which may not be able to happen".
Current F1 boss Chase Carey is confident of putting together a 15-18 race calendar, but Haas driver Kevin Magnussen thinks Carey's plan for "18 races in six months is really crazy".
"But if it's like that, then so be it and we'll see our families again at Christmas. I'm not saying it's impossible, but it's going to be a huge task."
Two-day race weekends are being mooted should back-to-back races have to occur, according to F1 sporting boss, Ross Brawn, to which Magnussen says: "Maybe that would be cool to try. We just want to race again as soon as possible."
Former driver turned commentator, David Coulthard optimistically thinks grands prix "will take place without spectators in the stands soon".
It is a brave prediction in a very uncertain time, and meanwhile Australian GP ticket holders still wait for a refund three weeks after the event was cancelled, which suggests a contractual battle over who foots the bill for the cancellation is taking place even though racing can't.
