catching a ball an than going out of play

Question
We had a girl that caught a ball in centerfield and then went out of play over the fence.  Is the batter out and then runners advance one base do to dead ball.  The umpirers ruled it as an out and let the runners advance one base.  If you need to you can see the catch on espn (emily nalan's catch).  Was just wondering the proper call.
Thanks for your time

Answer
The correct call would be dead ball batter out, no advance by the runners.  Or more accurately the runners would be returned to the last base touched at the time the dead ball occured, which would in all likelyhood be the base they occupied at the time of the pitch.