How exactly would you confirm - beyond any doubt - that contagion happened outside? Most people live most of their lives inside a building of one sort or another, so it'd be almost impossible to 'document' a case of outside transmission.
Even people from remote Amazon tribes in the jungle have got covid.
Also in warmer countries outdoor/indoor is not all that different ventilation wise. It is not like I am magically getting covid if I am standing just inside the door and am suddenly immune standing on the porch.
The closest thing we have is homeless populations - they spend most of their time exclusively outside - and they still get sick: https://www.sfpublicpress.org/covid-19-cases-spike-among-hom...
So making some big claim about how outdoors transmission is impossible is kind of preposterous.