Yes his explanation is bogus and there are lots of holes in it. "Ferguson gives the lockdown credit, which is *interesting* - the UK only began its lockdown 2 days ago, and the theory is that lockdowns take 2 weeks or more to work." Here was his initial prediction below vs his revised claim which seem to be vastly different.
"Finally, if the British government quickly went all-out to suppress viral spread — aiming to reverse epidemic growth and reduce the case load to a low level — then the
number of dead in the country could drop to below 20,000. To do this, the researchers said, Britain would have to enforce social distancing for the entire population, isolate all cases, demand quarantines of entire households where anyone is sick, and close all schools and universities — and do this not for weeks but for 12 to 18 months, until a vaccine is available.
“We might be living in a very different world for a year or more,” Ferguson told reporters. Source
Fast forward to a week later, "He said that expected increases in National Health Service capacity and ongoing
restrictions to people’s movements make him “reasonably confident” the
health service can cope when the predicted peak of the epidemic arrives in two or three weeks. UK deaths from the disease are now unlikely to exceed 20,000, he said, and could be much lower. Source
