Chimpanzees are known to raid rival tribes and eat the victims - it's a prize but they won't eat their own (I assume).
If the consumed are victims of raids then I kind of wonder if that is one of the origins of burials (evidence the Neanderthal's practiced it). If you bury your dead they can't be eaten by animals or rivals?
Also explains the small % of Neanderthal DNA. It was probably from war boot slaves from homo sapiens sapiens raiding Neanderthals?
It probably has to do with a previously unattested ingress of another human relative, such as “gracile” “anatomically modern” jokers who killed and ate their victims, then moved on.