A chair is still only as good as the persons posture. You can still lean forward in this chair and 'mess' your back up. Im 100% positive you could slouch in this chair and 'mess' your back up.
Still looks like a pretty comfy chair though.
This is true with any chair ever made. The point is that most of us don't do that; we try the opposite, to lean back for comfort. Most chairs don't do that properly leading to messed up backs.