Airbnb banned the host, without even bothering to find out who put the recording device there. Maybe it was the guest who put it there. So is this the way Airbnb works, guilty until proven innocent? Or maybe, guilty even if later proven innocent?
Yes it is generally likely that if a recording device is found in a home, it's the homeowner who put it there, but particularly if seeking to take serious action against someone, it seems reasonable to at least wait for a police investigation to be completed.