Also here :
“Neanderthals, Humans Interbred—First Solid DNA Evidence; Most of us have some Neanderthal genes, study finds.”
Your posted link contains a lot of interesting information. One suggestion is that interbreeding of modern humans and Neanderthals may have occurred around 60,000 years ago. My speculation is that the great Toba megavolcano around 74,000 year ago killed off so many of both groups, that they were glad to breed with anything humanoid they ran across. Scientists have suggested that only 5 to 10,000 humans survived this catastrophe.