two balls on field

Question
In a recent game, a ground ball was hit to shortstop. Just as the shortstop was about to receive the ball, a foul ball from an adjacent field landed on the field and rolled in front of the shortstop. The two balls simultaneously crossed paths a few feet in front of the shortstop. The shortstop fielded the ground ball but hesitated and did not make a play on the runner. The umpire ruled that the play should stand with the batter/runner remaining safe at first. I would like your opinion on this one. Thanks.  

Answer
Hi Jim,
This is a tough one because we have no rule that specifically addresses it.

It's not a blocked ball, interference or even a safety issue.

We do have a play going on with a live ball and umpires are limited on calling time during a live ball and play.

I'm going to agree with the umpire and let the play stand.  I can find no reasons or rule that allow me to do otherwise.

Mark