So didn't someone say something about Shyatt wanting Barnes and Williams to be different classes hence the red-shirt for Williams?
If that is the case, I assume Shyatt made the decision to play Barnes because he thought we was more ready to contribute in case he HAD to. He didn't know how Larry would respond, he didn't know Sellers would quit, he didn't know Herndon would get sick. But as a coach who has coached as long as he has, you know he anticipated something like that happening.
So since it did happen, I think he is ready to have Barnes play. That is why he was never redshirting. He was more ready than Williams.