Spencer memoir says then-Prince Charles sounded "giddily elated — like a lottery winner" after Diana died

Charles Spencer writes that then-Prince Charles sounded "giddily elated — like a lottery winner" in a call after Diana, Princess of Wales died in Paris on August 31, 1997. The claim comes from Spencer's memoir Swan Song: Diana, My Sister, excerpted in the Daily Mail ahead of its September 22 release. It rests on Spencer's account alone.