Is this really a shock? A lot of mammalian, and just about every primate species, modern humans incldued, is prone to sporadic to endemic violence. Was there any evidence that Neanderthals were any different in this respect?
It's a shock to the crystal-gripping New-Agey Earth-Mother types, who are just convinced that back then everyone lived in peace under a lovely mystical agrarian matriarchy, where everyone was attuned to Gaia, and there was no war or hate or sexism or racism or pollution or whatever. That is, until evil white men with their sexually violent technologically sado-masochistic patriarchal values went and f***ed it all up.
You probably think I'm exaggerating, don't you? ;)