This might be on Goodell, honestly we don't know. We're not in that players mind.
Before the witch hunt of defenders going high, he just might have tried to crush Gronk high.
But I do feel unfortunately this is going to be the norm, going low = no fine for defenders.
Going high = probably a fine when the incidental helmet contact happens.
Even when defenders target the chest and aim at the correct level, the ball carriers just turtle up, and lower themselves for contact. Defenders get fined even when they did everything right.
If I played defense at this point, man I'd be a knee huntin' fool. Save my paychecks.