It's not surprising that Johnson changed tack after the 250,000 prediction. He wouldn't have wanted to go down in history as the prime minister that ignored advice and allowed that number of deaths to happen. I don't wish to be critical, I'm glad it's not me having to make these decisions - what a responsibility.
But it has to be said that Neil Ferguson has a somewhat chequered history when it comes to these type of projections. They include the following:
2002 - up to 50,000 people in Britain could die from exposure to BSE - actual deaths 177.
2005 - up to 200 million could be killed worldwide from bird flu - 282 people died globally.
2009 - swine flu, reasonable worst case scenario was for 65,000 deaths in the UK - just 457 people died in Britain.
Fraser Nelson, whose article I linked has written a few articles over the last month or so about the "Swedish experiment" (his wife is Swedish so he has a personal interest). The Swedes thought that what other countries were doing in enforcing strict lockdowns was the "reckless experiment". They were baffled by the Imperial College projections. So far, it looks like they were right, certainly for their country.
https://www.telegraph.co.uk/news/202...ss-experiment/
Of course Sweden is not Britain, much less dense population etc. But the worrying point is that we are basing our strategy on Imperial College projections, which in the case of Sweden have been shown to be wildly out.