Good going!!
One time i let a friend sit in one of my ladder stands, right at last light a big buck came right to the stand and he shot it with his black widow and hit the buck almost the same place you did, just a little bit farther back.The arrow only went in about 3 or 4 inches and we only found a little blood. Latter that same year durring gun season i shot a 23 inch wide 10 point from the same stand.He had a healed up scar where the arrow had hit him.
You lucked out on that shot.