I was talking about this earlier this morning. I think the players had enough anxiety and pressure on them without him blowing up on them. Coach realized that if he was screaming and going crazy it could've added to the sense of desperation that the players were always feeling.
In most games where he has the calm pregame demeanor we seem to win 09 SEC champ, 11 BCS Champ. In last years regular season game against LSU he was constantly blowing up and maybe he realized that it wasn't helpful.
When we are blowing teams out it is only the fear of Saban yelling at the players that can keep them motivated. In this game there just wasn't a need for it. Great job by Coach.