There are two different targeting rules. The one you refer to has to do with the crown of the helmet. The other has to do with contact to the head or neck area. By rule the play in question was targeting and should have been upheld.I was flipping through 4 games last night but there was a call for targeting for a defender slapping the helmet of the receiver with his hand. Can't remember which game--maybe Clemson/Duke? UCF/Cinn? It was thankfully overturned as it was the most ridiculous I have ever seen. Zero contact with helmet to helmet. Literally hand to helmet. {facepalm}
Targeting and Making Forcible Contact With the Crown of the Helmet
ARTICLE 3. No player shall target and make forcible contact against an opponent with the crown of his helmet. This foul requires that there be at least one indicator of targeting (See Note 1 below). When in question, it is afoul. (Rule 9-6) (A.R. 9-1-3-I)
Targeting and Making Forcible Contact to Head or Neck Area of a Defenseless Player
ARTICLE 4. No player shall target and make forcible contact to the head or neck area of a defenseless opponent (See Note 2 below) with the helmet,forearm, hand, fist, elbow or shoulder.