That is a joke. From his angle he couldn't see if the ball was out of Dalton's hand or not. He just finished the tackle. It didn't look like a dirty play to me but I can see the penalty if they thought he went to far. A $20,000 fine for the play is ridiculous though. I know quarterbacks are the face of the NFL but these days a player can't breathe on them without getting a penalty or fine.
The angle doesn't really matter, you can't drag a QB to the ground by his head. Guessing the fine would have probably been less if it was a first offense, but he was fined $7500 for a hit on Delhomme last season.