It largely depends on how people view the radio station. If they always tell the truth, but just overestimate everything, than people will assume it is not as bad as the host says. If it is JUST the host the people don't trust is accurate, and they hear the insider talk about it, that will give them SOME faith, but it also depends on the record of how reliable his guests have been.
In short, it depends on the radio stations reputation. Better reputation means more people hear it, and more people spread it believing it to be true. (From your description, I assume the story would most likely be blown off as an minor event blown out of proportion)