if the components are the same left-to-right, i wouldn't be too worried about it. 1/2" isn't that much to be concerned about. if you are feeling ambitious, you could remove your rear sway bar to check if the arms are flat.
are your front ride heights the same?
I have had the rear sway bar out a couple times. That isn't a big deal at all. The front is money. Nothing at all wrong with the front... at least not that I have found. Level and stable!