Not a legal responsibility, an ethical one. Whether we like it or not, people tend to idolize public figures and believe what they say. When people regularly

Not a legal responsibility, an ethical one. Whether we like it or not, people tend to idolize public figures and believe what they say. When people regularly tune in to his show, they may be exposed to a certain topic / idea for the first time, and their only exposure to this idea may be what Joe Rogan and his guest have to say. I would say he therefore has a moral obligation to TRY not to mislead his listeners.