"Many of them are apparently experts on hanging and strangulation,"

I kinda am, short of a forensic anthropologist but I was the field researcher who witnessed the incidents first hand and investigated them.

This was indeed a homicide, his injuries are not consistent with a hanging, especially the type of hanging this would have been if he had done it himself. His feet would have been on the ground and he would have lent forward making himself pass out and ultimately die. This does not result in broken bones.

If he would have dropped a couple feet having all of his weight pull against the rope which was around his neck it is possible bones would have been broken in his neck but still not multiple bones.

Sounds to me is that someone tried to twist his head off to get the trauma he experienced.