People who attended the 2019 Pendulum Summit in the Convention Centre Dublin will be familiar with Boris Johnson's yarn about the movie "Jaws".

At the motivational speakers event, the future prime minister asked the audience: "Who was the real hero of Jaws?".

After fielding several mock answers, Mr Johnson unveiled the correct answer - not the Sheriff, not the shark - but the Mayor. Why? Because he kept the beaches open, and kept businesses in business.

The Jaws yarn was part of Mr Johnsons single transferable speech, the one he wheeled out on the rubber chicken circuit (veterans of the 2018 DUP conference told me they'd heard it all before: I caught some recycled snatches of it at the Tory party conference later in 2019).

But I didn't expect this fishy story to resurface in the context of a Covid inquiry.

And Dominic Cummings insisted at the health committee in Westminster that Boris Johnson said he should have behaved like the mayor in Jaws, as he regretted having a lockdown, and was resisting having another one in the autumn of last year.

And that was the point Mr Cummings said that he and Boris Johnson finally parted ways.

He said Johnson was more concerned about keeping the economy open - about keeping businesses in business - than he was about listening to the public health advice.

Among his many accusations were that Jonson did not understand the link between taking action to protect lives, which would in turn protect the economy.

Boris Johnson at the Pendulum Summit in 2019

That was the autumn, near the end of Dominic Cummings time in Downing Street. His bitterest commentary was unleashed on the government and its servants for their response to the start of the pandemic. Specifically in the week when the World Health Organization declared a pandemic - 11 March 2020.

This was in the middle of the Cheltenham racing festival, an event attended by thousands of Irish racing fans.

Some of them got sick from Covid-19 at the event, bringing the virus back to their communities.

Many wondered at the time why the British had allowed it to go ahead (along with a Champions League match, where Liverpool played host to Atletico Madrid and its fans - who could not watch matches in Spain at the time). The Irish Government had banned the Ireland-Italy rugby match a fortnight earlier.

On 12 March Leo Varadkar, then Taoiseach, strode out of the Vice Presidents house in Washington DC to stage an unexpected news conference, setting out the first of Ireland's lockdown measures.

On that same day according to Cummings, British politicians and top civil servants were at a meeting in the Cabinet room, comparing the plan for Covid to "old chickenpox parties", where people would get deliberately infected to get it over with.

Dominic Cummings told the committee that the officials and minsters were briefing leading journalists that a form of expected herd immunity was still the official policy, with a single peak expected in June, and enough people infected to make the country effectively resistant by September.

But he was also seeing numbers suggesting that if 60% of the population were infected, between quarter of a million and half a million of them would die as a result. The health service would be overwhelmed in a matter of weeks, and they had a matter of days to figure out a Plan B.

Then he and some close colleagues started to draw up the now famous whiteboard that Cummings tweeted out on Tuesday ahead of his appearance before MPs, the one that carried point six - "Who do we save?".

At that point - at around 8pm - Helen McNamara, the deputy cabinet secretary and second most senior official in Downing Street, came into the room and said, according to Cummings, "I've been told for years there was a plan for this (a coronavirus pandemic): there is no plan. We are in huge trouble. We are completely f****d. Thousands of people are going to die".

Asked by Jeremy Hunt, the former Health secretary (and Boris Johnson's opponent in the leadership race of 2019), if Cummings had advised Johnson to lock down Britain on Saturday 14 March, Cummings said yes - but it's more complicated than that.

He said there was no plan to lock down the country, no plan to seal the borders, no plan for test and trace.

Even if they wanted to lock down, they had no template to follow, no way to explain it to the public. Cummings claims it had to be invented from scratch, starting on 14 March. This included plans to shut down pubs, restaurants, sporting events etc.

Like a scene from Independence Day

"It was like the scene from Independence day where Jeff Goldblum says the aliens are here and your plan doesn't work."

This was Cummings describing a meeting on 14 March last year, at which he and his close aides set out the bad news for Boris Johnson - the assumptions on which the British government was planning its response to Covid-19 was not going to work, hundreds of thousands were going to die and the health service was going to break within weeks.

"It was completely surreal - like a scene from an out of control movie. We should have acted earlier, but we just didn't", said Cummings, with his hands on his head, his voice hesitant with regret.

From the middle of that week Cummings claims he had started to "hit the panic button" over the government's assumptions about the pandemic, and the plans it had drawn as a result.

According to his version, a small team of officials and advisors worked in record time to make up policies - ranging from the basics of lockdown to the funding of the furlough scheme (pandemic unemployment payments).

But just as they were starting to activate the policy, the prime minister himself came down with Covid. He was hospitalised (leaving staff in Downing Street asking what they would do if Boris Johnson died).

Vaccine planning when

The one bright spot Cummings pointed to was the vaccine procurement plan. But even that was more an accident of good fortune, rather than good planning.

The good fortune was that the Chief Scientific Officer was Patrick Vallance, who had made his fortune in the private sector, working in the pharmaceutical industry, and knew the vaccine business and the people who made vaccines.

He told Cummings that the usual public service procurement route would be too slow, that they needed a single responsible person who knows about the pharmaceutical industry. So they hired venture capitalist Kate Bingham, who has decades of experience investing in the sector, to run a rapid procurement.

More controversially, Cummings told the committee that he had been advised by Bill Gates and others to look at the novel mRNA technology, and use previous experience from big projects like Apollo and Manhattan (the atomic bomb) to do a lot of work in parallel, rater than in sequence - the normal public service way (this is because public investment wants to see if technologies work before funding the next phase of development: if everything was done in parallel, a failure of the technology would be vastly more expensive).

Cummings considered the risk worth taking because of the potential gains.

He claimed the mRNA vaccines, such as the one from BioNTech/Pfizer had been developed "in hours". He said the risk was so great from the virus that they (the UK government) should have moved to "challenge trial" immediately.

This would have involved getting 10,000 volunteers - half would be vaccinated, half would not. All would then be deliberately infected with Covid to see what happened.

"If someone died we would see that their family got a million quid or something," Cummings told the committee. He justified this on the grounds that "we could have got vaccines into peoples arms certainly by last September".

But would any government have sanctioned such a thing? None did.

It gives an insight into Cummings approach to problem solving - one that would find little backing from politicians, and goes a long way to explain his unpopularity with many backbenchers, who would have to carry the can if anything went seriously wrong in such a trial.

But what is less well explained is his particular venom towards the Health Secretary, Matt Hancock.

Health Secretary Matt Hancock

He told the committee Hancock should have been fired for 15 or 20 things, notably lying to everyone in the Cabinet room and in public.

But he gave little detail about what he meant. Except for one biggie - the care homes.

Cummings said the cabinet had been categorically told that patients returning to care homes from hospitals would be Covid tested before they left. But they were not. This was discovered in April, when the death rate in care homes had taken off alarmingly.

Hancock will have his chance to reply in detail at the committee - he is to be its last witness in this investigation. But he will also come under pressure before that appearance, as a result of Cummings tirade.

And Johnson will also come under pressure for denying in Parliament that he had made a comment about letting bodies pile up sooner than order another lockdown (Cummings says he heard Johnson say this in the Prime Minister's study).

But his most devastating charge is that all the chaos and bad decision making had one overwhelming consequence - tens of thousands of people died who need not have died if the government had acted sooner in ordering a lockdown at the same time as other governments across Europe.

While pro-government spinners are trying to make the specific charges levelled by Cummings go away by saying "there is nothing new in this, we have heard it all before," this one will be harder to shake off.

The careful and thorough questioning by committee members, led by former ministers Greg Clarke and Jeremy Hunt, suggests a careful report will follow.