But this doesn’t really answer the question. We could have easily used cloth masks then, if they advised it like now. The correct answer is they didn’t know the facts then and answered how the data showed them. He has been wrong and it’s ok to admit that
Except (of course) that there was no new substantive data that caused the change - it was pressure from holding an absurd position that masks don't work when they have worked quite well. It was ideology before and embarrassment after - not "science"