Those elbows from the plum clinch by Walker were some of the most brutal I have ever seen in the Octagon. He is tall as fuck, so he can generate a ton of leverage by pulling your head down with those long arms and lean frame. Roundtree was trying to get out of that clinch, at first he tried throwing a couple of hooks, but then he tried to squeeze his way out of it. As he went for the release to explode, Walker thrashed him with an accurate, flash elbow strike, which hurt him.
Then he was in survival mode, and Walker was just waiting to hit him with another elbow. You can see how calculated this guy was, after he landed the headkick and a punch or two, he immediately went for the Thai clinch. He knew what he wanted to do, he was anticipating those elbow strikes. You can tell because after he knocked him into the nether realm he celebrated by kissing his elbow.
The hipcheck was kind of funny IMO. It shows the guy has a mean streak in him, bad news when he is in the cage. I like it, he just cant make a habit out of shit like that.