I think the angle of the bend is actually opposite of the prop walk.
Actually, you would have had to have determined that at the time you recovered the anchor, assuming you could have seen the bottom. (My thinking was that you might have bent the shank yourself while power setting the anchor, given the bottom you describe.) N'any case, you might want to replace that anchor. Given the bottom conditions, a Fortress would be a good alternative with the further advantage that the Fortress comes with a lifetime guaranty in the event that it is ever bent/damaged. Tough pieces of gear and very reliable when used in the appropriate bottom conditions...