I think he got bit, and the confusion that followed cost him the fight (but I do think he would have lost anyway). But when they stood them up and it looked like he thought they were calling a foul. He pulled his mouthpiece out and was walking over to his corner. Then you can see that he sees Mike Kyle coming at him out of the corner of his eye and quickly shoves his mouthpiece in and turns to face him and defend himself and from that point it was all Kyle. It was funny when Joe Rogan asked him(Kyle) about it. Did you see him trying to quickly come up with an answer? He knew he was in the wrong, but didn't get called for it. It happens, what can you do. His excuse that his mouth was open and Sims was pressing his teeth into his chest is stupid, you had uppers and lowers, he clamped down. However, your right in that I don't think it was a bite hard enough to do any damage to him. I think he just thought that the ref saw the bit and was calling a foul.
I am sure the bite is bruised now, a little bit, it was fresh when the cameras were on it. Although you are right about him making excuses, he seems like one who it is never his fault. Personally the guy annoys me.
