Re: The Neanderthal must have been really drunk...
Kurten passed away long before the sequencing of the Human Genome let alone the Neandertal variant. He was writing about the facts as he understood them (the sterile hybrid was the accepted theory) and threw in a bit of fantasy to explain the interbreeding and a possible reason for the subsequent extinction of the Neandertal line.
Being able to tell a story does not detract from his ability as an anthropologist, else we might also discount the work of Robert L Forward and Carl Sagan.