I don't know that anyone was ever given a chance to beat him out. He was named the clear starter a couple of years ago, and they tied their wagons to him as the leader of the locker room. To beat him out, the QB would have had to be significantly better in practice, and from all indications, Leidner looks pretty good on the practice field when bullets aren't flying. Also, Claeys very clearly said at start of spring last year that he wanted to get Demry's redshirt back and be able to redshirt Green.
I think it's a leap to say that no one was as good or better. We just don't know. There are always examples of the replacement QB being better than who they replaced the previous year, even though they played behind the past QB.