If he's picking up the ball carrier, not just hitting hard enough to take him off his feet, and "body slamming" professional wrestling style, that's an immediate flag on my end. No warning here.
If he clearly drops him head first, either recklessly or intentionally, I would support an ejection for a flagrant foul. I'd have to see it to be sure, but that's not a move that has any place in the game.