Unfortunately, respectable publications have been pushing that paper recently as proof we knew about asymptomatic transmission back in January for stupid, partisan, political reasons.
It's very easy to forget that current decisions and past decisions operate on vastly different kinds of knowledge.
It's easy to look back in time and say "Someone knew the right answer."
It's very hard to stand in the present and say "Of the 20 people who each have a different answer they believe is right, I am going to select the really right one."
Often, the optimal decision is to hedge and delay until information becomes clearer.
