By some accounts, the Prime Minister didn't do too well during his half-hour of scrutiny on the Sky News Special, being interviewed by Faisal Islam and then questioned by a sceptic audience.
What to me really stood out though was Mr Cameron accusing the "leave" campaign of refusing to spell out what the country would look like after Brexit, instead trying to reassure us that it was "all going to be okay".
This was almost exactly the line taken earlier in the day by George Osborne, who joined forces with his Labour predecessor Alistair Darling, to write a letter to Vote Leave condemning it for "making up" its plans for Brexit.
In their letter, the pair wrote: "You are coming forward with uncosted and unworkable proposals that would damage our country by taking us out of the single market upon which so many jobs depend". They added: "It is simply not good enough to pretend to the British people that they can vote leave and there would not be profound and negative economic consequences that would affect them and their families".
To conclude their letter, Osborne and Darling demanded that Vote Leave spelled out the "specific trading relationship" Britain would have with the EU after Brexit and offer "guarantees" on trade tariffs.
The day previously Vote Leave had breached their own self-denying ordinance on releasing any post-Brexit plans, by publishing its proposals on immigration. But no one is expecting it to respond to the chancellors past and present, or even the Prime Minister by producing more detailed plans.
The Economist sees this lack as a "fatal contradiction".On the one side are the anti-regulation heirs of Margaret Thatcher like Michael Gove who want to turn Britain into the Singapore or Hong Kong of Europe. On the other side are the nativists who resent immigrants on cultural, as much as economic grounds, and who favour protectionism over free markets.
The working class voters who like the "leave" campaign on nativist grounds would probably be horrified by the economic agenda of Gove and his colleagues. The Economist believes that this is why we don't hear the "leave" campaign spell out all the EU regulations they would like to abolish, which would include those on workers' rights and why Boris Johnson burbles on inanely and inaccurately about bananas and teabag recycling. It's a distraction from the unpopular part of the "leave" agenda.
Nevertheless, the "leave" campaign would be wise to reconcile its differences and produce a plan. When the Adam Smith Institute (ASI) took it upon itself to publish a plan by our own Roland Smith, it triggered positive responses from across the political spectrum, culminating in highly favourable comment from Ambrose Evans-Pritchard in the Telegraph.
That Ambrose lumped together the ASI paper with Flexcit, however, is hardly surprising. Roland based his paper closely on our work, removing any references to it as a way of secreting the message into the "bubble". The very mention of Flexcit in some quarters causes nose-bleeds.
By so doing, Roland managed to demonstrate that, once shorn of its identity, there is a real demand for the ideas expressed in Flexcit. Again that is not surprising. Coherence and credibility are watchwords for any successful campaign and Flexcit provides precisely that to a campaign that otherwise lacks direction or substance.
The absence of a plan has been a liability throughout the entire campaign. Had there been one published at an early stage it would have deprived the "remains" of one of their most powerful memes and thereby reshaped the entire campaign. We would by now have spent many months talking about detail and the very specific direction of travel in which Flexcit takes us.
Even now, as the media tardily wakes up to its presence, "bubble-dwellers" are still not fully – or at all – getting to grips with the thinking behind our title. They certainly have not understood that it represents a flexible and continuous response to the complex process of leaving the EU. By "flexible", we are not committed to any one mechanism of exit and, while preferring the Efta/EEA option, we have numerous fallbacks.
This is something Lost Leonardo called a "revolution in public policy-making", the product of several years of reporting on the EU, pulling in a vast array of sources with absolutely essential input from Eureferendum.com readers and fellow bloggers. It is a real testament to the quality of our readers.
From this experience, we have the most comprehensive study on the subject anywhere. Our pool of solid expertise leaves more prestigious entities standing. That's because we have not underestimated the complexity of the Brexit process. We have spent the time and effort doing the research - at the same time opening up our work to continuous scrutiny and responding to the critiques.
We started with the assumption that there is no magic wand: the two years allowed under Article 50 would not be nearly long enough to unpick forty years of political, economic and social integration. To even get close is implausible. Moreover, the more radical the process, the greater the risk. Anything perceived to be risky would deliver us a referendum defeat.
From that point we arrive at our guiding ethos. Brexit is a process, not an event. Leaving the EU will have to be done in phases. The first phase simply takes us out of the political construct of the EU. Only then do we look at the long road of full separation.
When asked what does Brexit looks like the day after, the answer is simple: exactly the same. By remaining part of the EEA, with a transitional agreement on fisheries and agriculture, maintaining most of the cooperation agreements and adopting the entire EU acquis into British law, nothing changes. This is the quickest settlement to negotiate, the least disruptive and the solution most likely to be ratified without a fuss.
Necessarily, this requires compromise on freedom of movement, an idea which is met with howls of rage from those less familiar with the subtleties and complexities of the plan. They wish to ditch this policy in the mistaken belief that it will have a significant effect on overall migration.
To accommodate this rejection, they assume that we can rely on WTO rules or whip up a customised treaty in two years flat and them resume normal politics. These are flawed assumptions.
We have always said the EU is more than just a trade bloc. There are multiple levels of invisible government which have gradually integrated over the years. These must be unpicked with a scalpel, not an axe. As much as we might like to go at it like a bull in a china shop, we don't have that luxury. Britain's soft power is hard-won on the basis that we uphold our agreements and respect treaties. Moreover we will still wish to have amicable relations with the EU and so compromise will be required of us.
The wisdom of this approach is that it removes any cliff edges and takes the drama out of Brexit. It makes it a much easier sell. Hardliners don't like it but they will vote to leave come what may. It is the "undecideds" we need to convince. Though it does not immediately satisfy many of our requirements we are at least out of the EU - for good.
The plan also presupposes that a successful EU exit should be the foremost political priority of the "leave" campaign and that any, indeed, every other issue, should play second fiddle to securing a majority vote in an EU referendum. Of necessity that means repudiating many of the tired old "eurosceptic" (a word that must now be retired) nostrums that have failed to arrest, let alone reverse, the ongoing process of political and judicial integration to which all EU Member States are subject.
The transition plan rejects empty aspiration and embraces pragmatic and practical political reality. It is not a contradiction that those who are amongst the most determined advocates for Brexit sound like the reasonable centre ground. We have put ourselves in that position deliberately because we know that is where we need to be in order to convince the mass of undecided referendum voters that leaving the EU is not only necessary, but also practicable, possible and safe.
In offering our plan, we recognise that the EEA option is far from optimal. We habitually call it the Norway Option, perhaps unwisely, but it is a departure lounge rather than the destination. This of course prompts the mantra: "Still pay, no say". And then there is the tired "fax democracy" canard.
But in the process of producing Flexcit, we became increasingly aware that the EU is not the top table in regulatory affairs. In fact, the EU is now superseded in most areas, adopting regulations from many global bodies wholesale. We have seen how the United Nations Economic Commission Europe (UNECE) is pivotal to several key areas of regulation. We have also explored the role of Codex and standards bodies which now form the basis of what we regard as an emerging global single market.
Far from having no say, we find that the EU is increasingly an obstruction to us having our say, removing our independent vote and right of opt out. It seems the entire case for remaining in the EU is perpetuating the myth that the EU is the alpha and omega of rule-making. It just isn't so.
We find in the very first instance that Britain is free to pursue its own trading avenues and has an enhanced role in the formation of regulations. Consequently we become a leading voice in bringing that global single market closer to what we have achieved in Europe. The argument for going into the EEC in 1975 was that we needed to be in it to have a say in the rules. If that was true then, the same logic applies now - but on a global level.
We set out in Flexcit the many opportunities this presents along with the process of modernising our aid, trade, fishing and agriculture policies after we repatriate them. But having dismantled much of our administrative capability and expertise while inside the EU, we really don't want to bite off more than we can chew.
We identify how we can reform immigration without doing anything as drastic as ending freedom of movement and without leaving the Single Market. We show how our agility gives us leverage over the EU to reform it from outside in ways we cannot from within. Effectively Flexcit gives us the reforms Mr Cameron pretends he has already secured.
How we then evolve becomes a matter for a national conversation. But it will become clear that the current structure of government and the politics within is inadequate for the task at hand. To that end we put forth our own proposals for democratic reform, to ensure our politicians never do this to us again without our consent. That is the true destination of Flexcit and the entire point of it. We're not in this to prune a few regulations and save money.
For all that, we are under no illusions. Leaving the EU is not only a revolution in our relations with the Continent. It is also a fundamental restructuring of domestic governance, involving a long-overdue reshaping of the post-war settlement. Not by any means do we underestimate the gravity of what we propose.
That is why we need to win the intellectual argument - and why we need a plan. Flexcit demonstrates that this can do this without undue pain and without unacceptable risk. At the end of the process we have a United Kingdom fit to do business with the world as it is rather than how it was when Mr Monnet dreamed up the European Union.
Yet, only weeks now from the referendum, we're still discussing the basics. Roland Smith is still having to hide the true source of his papers for fear of offending the "nose bleeders". And Mr Cameron is thus able to get away with criticising the "leave" campaign for not having a plan, when we've had one all along.
If we then go on to lose the referendum, we will have doubt as to the reasons. Yet, even if we are thus unable to leave the EU, the fight does not stop there. We are not only taking on the EU but also our own political system. One of our first tasks is to break the "bubble". Only when we are free from its malign influence will we be able to make any serious progress.
Pete North and Lost Leonardo (Independent Britain blog) contributed to this article.