Check out the link I put on reply No. 15. It's a site devoted to de-bunking Urban Legends, which, as you know, are hoaxes.
Normally they are very reliable but I am going to independently check this one out. When I am wrong I admit it. Urban legends could be wrong on this one or perhaps Paul Harvey took so much flak or was misquoted (or was in fear of his life) to the point that he denied having used that piece. Another possibility is that he picked up erroneous information himself, from here for all I know.
So there!
Stay tuned for the rest of the rest of the story.