[rbmartin]

In a little league game I was helping coach, the following play took place:
Runners on first & second. Ball hit directly at the shortstop , who was playing inside the baseline. Ball passes through the shortstops legs and hits the runner behind him as he is going to third. The umpire (Just a Jr. High kid trying his best) called the runner out. I didn't question the call (we were way, way ahead so what's the use) but a don't think he should have been called out since an infielder had already had a legitimate chance to field the ball.
1) Was the umpire correct?
2) If not, how do you resolve this play (ie,. play on, dead ball with runners advancing, etc.)?
3) Where in the rules may I educate myself further on this subject?