Ferguson’s 500,000 figure was pure fantasy as demonstrated by Sweden.

according to calibrations from researchers at the universities at Lund and Uppsala, based on the Imperial College report, were supposed to be between 85,000 and 96,000 — the Swedish death toll stood at less than 6,000.

That’s not just wrong, that’s catastrophically and indefensibly wrong. From those numbers alone it is futile and puerile to present that “we didn’t do nothing” when, in fact, we should have done nothing.
Fergusons models, which have a solid history of being catastrophically wrong (as illustrated), were torn apart by numerous people including Google engineers who were appalled that he was using an obsolete language with millions of lines of unverified code, something abandoned decades ago.
Even in light of all this, our government utterly ignored that the man was, and remains, utterly incompetent and should be, at the very least, stripped of his academic qualifications thereby rendering him unemployable by any academic entity.
Instead of listening to far better qualified individuals than Ferguson, our government and the media shut them down.
Hundreds of thousands of lives have been lost thanks to our governments reckless behaviour, and officials including Ferguson need to answer for mass homicide or nothing will stop them from doing it again.

Graeme, you are missing one of the key claims coming from the Ferguson model, as noted in the article: not just the headline number, but that many “could die in the space of a couple months”. The implications of the claim were likely to be more deaths even than the headline numbers, because it implied metrics such as COVID patients alone requiring more ICU beds than available in the U.S. (and even worse in the UK, which has fewer ICU beds per capita). That was based on an assumption that SARS-CoV-2 infections would rise inexorably until hitting a calculated herd immunity threshold (>50% of a country’s population).
Instead, what happened even in areas that didn’t mandate stringent lockdowns in response to rising COVID numbers – such as Sweden and multiple U.S. states – was that initial COVID waves lasted roughly 6-8 weeks and infected perhaps 15% to 20% of the population before subsiding. One can debate the precise reasons for this, but it appears to result from some combination of seasonality, social structure (not everyone is connected to everyone else, so some chains of a respiratory virus can run through a connected group and then “burn out” by failing to jump to others), and voluntary measures (such as some businesses choosing to have employees work from home even in the absence of mandates to do so).
That last point – voluntary measures taken by private businesses and citizens weighing their own view of costs and benefits – is categorically different from mandated lockdown because it respects basic principles of liberty in a free society. It’s also likely to have a far better ratio of benefits to costs than blanket mandates because it decentralizes decision-making to private actors aware of their own circumstances when deciding whether or not to implement these measures.
Should Ferguson (and other epidemiologists) have been aware of this possible in the Imperial model? I would argue that they should at least have noted it as a qualifier, given the history of other respiratory virus epidemics (specifically pandemic influenza). These similarly followed seasonal/cyclical patterns where areas experienced multiple waves, with the first waves subsiding well before total infections hit a theoretical herd immunity threshold. And recall, of course, that the actual policy actions taken in response to the model’s prediction were the largest peacetime restrictions ever imposed on the populations of Western Europe, the United States, etc.