Obstruction interpretation

Question
Kevin,

My 9 year old team recently had the following situation happen:
1) runner from third attempted to score on a ball hit to RF;
2) catcher throws his mask off and it lands on the third base line about 3 feet from plate;
3) runner decides not to slide due to the mask location and ends up tagged out;
4) I questioned the issue of the mask as obstruction and the other coach disagreed;
The youth umpire did reverse the call, but I subsequently found nothing in the rule book about defensive equipment (i.e. mask) also creating obstruction.

I realize if the bat was laid there by the batter, that is different.  The only exception to this seems if the bat is moved by the defense to a position which impedes the runner from sliding or reaching the plate.

What is your opinion on this situation?

Thanks.

Answer
I have not heard or read of anything regarded defensive equipment either. It is up to the umpire to clear the plate area if he sees that a play is coming. Also, a mask that is 3 feet down the line doesn't seem like something that could change the result of the play. All it would take to avoid the mask is running about a foot to the right or left.

To me this is a play that the umpire screwed you on and realized it so he overturned the out. I would have let it go the way it played out (I would have moved the mask though).