Leading with the forearm like that should be an instant exclusion offense, regardless of the circumstances. Even so, I take issue with some of the stuff in that video.
First, when you watch that hit full speed, I have to call BS on the commentators who say the defender had time to pull out of a hit. I see roughing the passer calls all the time where the defender has no chance to pull out of the hit because they are already airborne or falling on the QB. Human reaction time and physics are what they are, and cannot be changed. American Football is a rough sport, and people are going to get hurt.
I call BS on them again for saying Lawrence is clearly in the sliding posture. Sure, easy to see from the side of the pitch with multiple camera angles. From the defender's perspective? I'm not so convinced, and again it comes down to the time taken for the defender to see, process, decide what to do, and his muscles to act on that decision.