I never was all that impressed with BB either. He didn't seem to be ready for the role and it always felt like the only reason he was playing was because he had a deal with the sleaze ball POS coach and he didn't earn the position. That's what the team thought too if I remember correctly.
The other backs impressed me more and no I'm not a coach but I have seen many great backs at UT. He just seemed a step slower and didn't have as much speed/natural ability as the other backs that came in.
Some are saying he was hurt, that might explain it but I just didn't see the results on the field.