The point of the torn note is (as far as I understood) that the authenticator keeps the other half. So anyone can contact the authenticator and ask them if they

The point of the torn note is (as far as I understood) that the authenticator keeps the other half. So anyone can contact the authenticator and ask them if they have a counterpiece for any given note. I don't see how this prevents someone with visual access to the note and the painting from creating a fake though. (The article mentions the tear is hard to reproduce but I doubt that.) Additionally I don't see how this prevents anyone from distributing a valid note with a fake or wrong painting.