Here's the relevant provision from the indicator about leading with the helmet, etc.

Leading with helmet, shoulder, forearm, fist, hand or elbow to attack
with forcible contact at the head or neck area

Notice how leading with one of those body parts is not enough; it has to be done for the purpose of attacking the head/neck area with forcible contact.

This requires refs to consider purpose or intent when applying this specific indicator. Was the defender leading with their head in order to crash helmets with the defenseless player, or were they running, head forward, as all humans do? Did the defender's arm contact the head of the defenseless player as part of an intentional striking motion, or was their arm swinging as part of a natural running motion? etc. 

I've definitely seen hits like that be called targeting. But I've also seen hits like that go uncalled. At the end of the day, I don't have a problem with the outcome, especially since (1) it wasn't called live, (2) the booth buzzed in to assess for targeting, and (3) after review, the booth also determined that it wasn't targeting.