The whole episode is a nice and timely reminder of the difficulty of the society as a whole in dealing with scientists and understanding which ones are good, which ones can be trusted, etc. Academic societies such as the RS help, but as this shows they are by no means perfect, and can be gamed and manipulated when the stakes are high enough. It is a real challenge though -- how do you trust a scientist without having to learn all the science they are telling you about?
But do general people know who is a scientist and who isn't? How do they find out?
It isn't by membership of a learned society, it isn't if they are working at a university. There is no simple way for a general person to know if somebody is a scientist.