What a Catch!! or Not?

[Frank Lemon]

http://youtube.com/watch?v=5ZxqUjklqQI

I'm sure many of you have seen this play, and based on Rules Supplement #20 in the 2007 rulebook, in my opinion this should be an out. But what if she is standing on the collapsed fence prior to catching the ball in what would have been home run territory?

The rule reads in part, "when a collapsible, portable fence is used and a defensive player is standing on the fence when the catch is made, it is a legal catch; therefore a defensive player should be able to stand on a fence that has fallen or is falling to the ground. As long as the defensive player has not stepped outside the playing area, the other side of the fence, the catch is legal."

So if the fence falls toward home run territory, does it essentially extend the field? Can the defense stand on a collapsed fence in what was home run territory just seconds earlier, and make a legal catch?