You always see the head coaches being led off the field at the end of the game by State Troopers. I never see that at Ohio State, USC, Penn State, Notre Dame, etc.
Did that start with Bear Bryant? He was (is) such a God in Alabama that maybe they thought he should be sheilded from the masses wanting to touch his garments.
'The Bear' once wore a helmet (Football helmet) going on to Grant Field so the thrown whiskey bottles wouldnt kill him. Maybe it started around that time