The government keep pretending that we did all we could at the start of the epidemic and the problem was that we didn't know about asymptomatic transmission until much later...
But SAGE's own minutes show that this was not true!
assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/888771/S0372_Fourth_SAGE_meeting_on_Wuhan_Coronavirus__WN-CoV__.pdf
Papers already existed suggesting it was a thing:
jamanetwork.com/journals/jama/fullarticle/2762028
www.nejm.org/doi/full/10.1056/NEJMc2001468