The correct explanation for the apparently different directions of shadows in that photograph is much simpler. The terrain is sloping. Look closely, the picture was taken from above a depression in the surface. The terrain on the right slopes down towards the center and the terrain on the left slopes down away and towards the right causing the shadows to LOOK like they are coming from different directions. It's just hard to make that out because the lack of scattering and the "blown out/overexposed" lunar rigolith provide little reference for out human brain to "align" the world like we can on pictures taken on earth.