Aerosol spread of Covid-19 is a thing.
I've been surprised at how little the possibility of Covid-19 aerosol transmission features in official rules or discussion despite more and more published proof. I can't tell if they know something I don't, they're deliberately ignoring the data because it would mean painfully strict rules or they simply aren't aware.
Whatever the case, Kottke points to what seems to be a clear case of aerosol transmission in a spinning studio where all official hygiene and distancing rules were followed.