In the 2nd quarter, Booker caught a pass - or at least appeared to - for a first down. He was tackled and the ball came out. There was a scramble for it, and the officials ruled the pass was incomplete.
Saban had thoughts about challenging the ruling, but the officials said he was unable to because they ruled it incomplete.
This is incorrect...that was last year's rule. This year's rule is to play to whistle, and to allow for a wide range of issues, including passes that were ruled incomplete.
In other words, the refs messed up.