Which word in which decision?
Should have read your local rules first, a mistake a lot of people make. Might have been an area designated free relief, might have been a hazard (a drain area is not always a hazard, unless designated and/or marked as such). Local rules might have told you to stay off of the man-made slope. Otherwise, it's golf, play it as it lies---you don't get relief just from an unnatural stance.