The expert advice changes, not infrequently, during this pandemic. And that applies even when that “advice” comes in the form of a one-liner.

As criticism mounted over the slowness of the vaccine rollout, Scott Morrison and his ministers have been increasingly dogged by the PM’s claim, especially early on, that the vaccination rollout was “not a race”.

Despite it being very obvious it was indeed a race to get the job done, once the line was in the script, ministers parroted it or struggled with it.

And it has become a media favourite for “gotcha” questions, as we saw at the weekend.

On Sunday Deputy Prime Minister Michael McCormack said on Sky, “It’s not a race – it has to be systematic, it has to be rolled out in a way that Australians obviously need to know that they have to get the jab, but we can’t have everyone getting it at the same time.”

Trade Minister Dan Tehan, over on the ABC, ranged widely to explain the nature of “races”.

“The Melbourne Cup’s a race, the Stawell Gift’s a race. When it comes to vaccines, what we’re trying to do is make sure we get as many people vaccinated as quickly as we possibly can.”

In question time on Tuesday, Labor asked whether Morrison still said vaccinating all Australians, including aged care residents and workers, is “not a race”.

Morrison reached immediately for a human shield – an expert.

It was Brendan Murphy, the secretary of the health department, who first made the statement, the Prime Minister said. And his words – which he stood by – were based on Murphy’s “expert advice”.

Murphy, formerly chief medical officer, has become a well-known face during COVID-19 from all those news conference appearances with Morrison and Health Minister Greg Hunt.

Morrison said he “affirmed” Murphy’s remarks – “because all the way through this pandemic our government, the governments around the country […] have always been mindful of the expert advice informing the decisions we have taken”.

For good measure he tabled Murphy’s words.

By happenstance, Murphy was appearing before a Senate estimates hearing on Tuesday afternoon, so he was quickly interrogated by Labor about whether the PM had thrown him “under the bus”.

Murphy indicated his own language has now changed. (Not that it was his place to advise Morrison on language, he stressed; the PM “has his own advice on language”.)

“I think I did say it way back in January at a press conference, when there was this discussion about racing through the TGA [Therapeutic Goods Administration] approval process, and I think I did say it’s not a race at that time,” he said.

“It is a term that I did use, way back then.”

But “we’ve moved on”.

“It’s not a very helpful phrase now because we’re going, we’re in action, we’re fired up and we’re doing it as quickly as possible.”

The critics dispute strongly the extent of the firing up. And key details continue to be lacking, as was evident, to the government’s embarrassment, on Tuesday.

The Minister for Aged Care Services, Richard Colbeck could not say how many of the aged care workforce have been vaccinated.

Because these workers are getting their jabs in various places – including their work sites, GPs, hubs – total figures are not available. Another complication is they don’t have to inform their employer whether they have been vaccinated.

Belatedly, the government is making arrangements for more extensive data to be quickly collected.

“We’re asking the aged care providers who hold the data to report that information back to us,” Colbeck said. “We’ve asked them to report that alongside their flu vaccination data.”

On the latest figures, produced in Senate estimates after confusion, 39,874 doses have been administered to aged care workers nationally – 10,608 in Victoria. Some 32,833 people have been fully vaccinated, 8027 of them in Victoria.

The aged care workforce is about 366,000 nationally. Of these 235,764 work in residential aged care, and the rest in home care.

Whatever the number actually vaccinated, Colbeck said he was “comfortable” with the pace of the rollout.

Hunt, who every day bombards the media with numbers, had to admit he had been wrong in his figures about the aged care facilities covered in the vaccination program.

He said on Monday that Australia-wide, six were still to get initial doses, On Tuesday he said he’d misread the advice and it was 20. “Nobody else’s fault but mine,” he said, offering a rare apology.

Tuesday night came an update saying only 14 facilities remained. All but one are scheduled to be done by June 8. None is in Victoria.

There were sighs of relief from federal and Victorian governments that the latest three COVID cases in Victoria had not involved aged care workers or residents.

The state government has announced a drive to get workers in aged care and disability vaccinated over the next few days, with special lanes at hubs so they avoid the queues.

“This is very much a call to arms for those workers on the frontline to come out,” the state Minister for Disability, Ageing and Carers, Luke Donnellan, said.

Very obviously a race.