Pink Floyds official stance on the subject has always been that they really dont know what people are talking about. But in some past interviews they have hinted at it being real. Also, about 10 years ago, an LA based radio talk show host took the claim of being the one who had started that rumor, and that it wsa indeed false. He was shot down within minutes of his testimony. And it really is, sober or not sober, to close to be a coincidence.
On a side note, ever see the little person hanging himself from the tree in the background of one of the yellow brick road scenes? Suppoisedly not real, but there is something definitely falling from the tree.