Haws went down to defend and that would have been fine to hold defensive position with the forearm but he saw the ball was rotating to the wing so he rotated back, but before doing so hit him anyway. That's why it looked dirty.. How in the world is running over to a player at the high post off ball and shoving him in the back not a foul? You can't just knock players over so they can't catch the ball, That's a foul. There is a difference between what the OP is describing getting posted up and what Haws did. You can't run over a player through a screen. You can't charge over a set player with the ball. You can't do what Haws did either.
Again, the announcer reacted in real time, and in real time I thought it looked uncalled for as well. Still do. Watch Haws feet, he does a double step for momentum to hit him hard. He for sure had intentions to hit him hard in the back. If their guard hit any one of our players like that in the lower back, I wouldn't be happy at all. I would not think it was okay because it was a "basketball" play.