Why would the UFC use Bones Jones spinning elbow to the back of his opponents head on a highlight reel. It's a wild reckless illegal technique. It happens so fast there is no way for him to know that it wont land to the back of the head. At that speed the official isn't going to be able to tell where exactly the blow lands. If his opponent stepped around and ko'd him with an overhand right in the same spot Joe Rogan and his mindless parrot counterpart Mike Goldberg would whip out a violin instantly. There isn't enough of an objective opinion with these two. They sound like a couple of used car salesman to me.
I don't think he is a "dirty" fighter I just think his technique is what you said, wild.
Now Joe Rogan... He's awesome. Watch some other shows and you'll wish he was there. He is a little opinionated but that's because he is a fan too. The only person I've never heard real bias from is Militich but he's no Rogan when it come to the "play by play."