HaleiVi,
He wouldn’t have said “it is just said over by the Hamon Am”, unless he knew that it wasn’t found anywhere. He could only know that if he knew all legitimate sources. Since as you say, he doesn’t, he probably didn’t say it. The only alternative I can think of is that he has somewhere in Chaza”l where it is implied that it’s not true, but that doesn’t seem to be the case.