You noticed. Yes, he is shooting right again. I have a friend whose opinion that I respect very much that knows pretty much all there is to know about archery. In his opinion, it is more important to have him shoot from the dominant side of his back instead of the side of the dominant eye. There are trade off in each (as there is in pretty much everything archery related), however the benefits of shooting from the dominant side of the back seem to outweigh the dominant eye side.
FWIW it has made a difference.