I don't know about 900. 12 balls in the pocket will very seldom carry, much less 36. It is possible, but why does this kid only shoot them when nobody is around to visually verify them?
Also, I believe that the USBC rulebook requires that a league officer is present during the pre/post bowling in order for the scores to count. Was that the case here? 3 times? I find that hard to believe.
Mike