What, the "scientists" didn't know how viruses spread among the humans? The first rule, btw, is: if you're unsure about the method of transmission, you assume the airborne transmission. That means masks and goggles, travel stop and quarantine. To say that they didn't know is true, partially. What is entirely false is the notion that it was the "evolving" knowledge that led us to masks. Bullshit.Agreed he did say thia at first because of the shortage of masks for overwhelmed medical professionals, and the fact they were still learning about the virus. As they learned more about it, and how it was transmitted, and that cloth masks could work, then he changed his advice to everyone wearing masks. This is what scientists do, they follow the evidence. That sometimes means changing your advice. It is disingenuous to portray this any other way.