You’re right that these calls are highly subjective. Here is what I took from the video:
1. Keep your head up (Spielman says all the time to see what you hit)
2. Don’t aim for the other guy’s head or neck
A hard shot to the chest, like Ward’s hit, should not be a penalty. But those will be called sometimes because players move as a hit occurs.
This doesn’t address noncalls either like the hit on Haskins in The Game last season. It’s an imperfect solution to the player safety concern. But I appreciate the attempt to clarify.