I think the main confusion on targeting is that there are two situations. One where the defender leads forcefully with crown of his helmet. Second is the defenseless player hit, and doesn't have to be helmet to helmet - it just has to be a hit in head or neck area with helmet, shoulder, arm, etc.
They normally get the helmet-to-helmet correct and it's obviously. But the defenseless player hit is the one that no one seems to understand and where I think people get confused. Announcers don't help either when they say - "looks like he hit with his shoulder and not the helmet, that shouldn't be targeting"