re: How was the Alabama player not ejected?

Targeting and Initiating Contact with the Crown of the Helmet (Rule 9-1-3)
Targeting and Initiating Contact to Head or Neck Area of a Defenseless Player (Rule 9-1-4).
No change to the statements of the fouls. Changes to the penalty statements in bold:

PENALTY - 15 yards. For dead-ball fouls, 15 yards from the succeeding spot. Automatic first down
for fouls by Team B if not in conflict with other rules. For fouls in the first half: Disqualification for
the remainder of the game. For fouls in the second half: Disqualification for the remainder of
the game and the first half of the next game. If the foul occurs in the second half of the last game
of the season, players with remaining eligibility shall serve the suspension during the first game
of the following season. The disqualification is subject to review by Instant Replay (Rule 12-3-5-
f).
For games in which Instant Replay is not used: If a player is disqualified in the second half, the
conference may consult the national coordinator of football officials who would then facilitate a
video review. Based on the review, if the national coordinator concludes that the player should
not have been disqualified, the conference may vacate the suspension. If the national coordinator
supports the disqualification, the suspension for the next game would remain.  

Notes to 9-1-3 and 9-1-4
Note 1: “Targeting” means that a player takes aim at an opponent for purposes of attacking
with an apparent intent that goes beyond making a legal tackle or a legal block or playing
the ball. Some indicators of targeting include but are not limited to:
• Launch—a player leaving his feet to attack an opponent by an upward and forward
thrust of the body to make contact in the head or neck area
• A crouch followed by an upward and forward thrust to attack with contact at the head
or neck area—even though one or both feet are still on the ground
• Leading with helmet, forearm, fist, hand or elbow to attack with contact at the head or
neck area
• Lowering the head before attacking by initiating contact with the crown of the helmet

Note 2: Defenseless player (Rule 2-27-14):
• A player in the act of or just after throwing a pass.
• A receiver attempting to catch a pass, or one who has completed a catch and has not had
time to protect himself or has not clearly become a ball carrier.
• A kicker in the act of or just after kicking a ball, or during the kick or the return.
• A kick returner attempting to catch or recover a kick.
• A player on the ground.
• A player obviously out of the play.
• A player who receives a blind-side block.
• A ball carrier already in the grasp of an opponent and whose forward progress has been
stopped.
• A quarterback any time after a change of possession