
Here is Exhibit A for how far the NFL goes to protect quarterbacks.
Los Angeles Rams defensive lineman Aaron Donald was called for a personal foul penalty in the third quarter of Thursday night’s game against the San Francisco 49ers for this hit on Brian Hoyer:
This was roughing the passer on @AaronDonald97 smh #LARvsSF #LARams #TNF #NFL pic.twitter.com/oMJjxJvIcf
— Andrew Tashian (@Tashville401) September 22, 2017

Donald was coming after Hoyer with pressure and was a step away from the QB when Hoyer released the ball. There was no way to stop his momentum, and his hit was perfectly legal. It was as clean of a tackle as you can get.
Yet Donald was still called for roughing the passer, probably because the official thought he punished Hoyer too much with the hit. Unfortunately, defensive players are at risk of being called for penalties simply for hitting the quarterback too hard.