I dont really think he was "dropped". I think he more caught a funny punch and felt down on his knee.
But I do agree with wondering out his chin. He seemed very stange in the stand up early, but as it progressed he had a decent 1-2 going on, and his ground game was very impressive, even if his opponent was a lot smaller. In TUF, people tend to blitz you and he will have to watch out not to get caught early before his striking comes together. Good season.