"Continuous Action"?

[Yeggman]

USSSA
Bases loaded, 1 out.
Batter hits a pop fly behind 2nd base which I judged no one could catch with ordinary effort. R1 (on 3B) took off as soon as the ball was hit. Center fielder raced in and tried to make a diving catch, but the ball hit her glove and rolled away. R2 and R3 froze to see if F8 would catch it. By this time, R1 had scored. SS picked up ball off the ground and threw to 3B to force R2 who then threw to 2B to force R3 for the double play. Offense's coach comes to me saying, "the run scores right because it's a 'continuous action' play". I say no way, I've got 2 force outs, therefore the run cannot score, even if she scored an hour before the force outs were made. He and his coaches think I just don't know the rules. I say there is nothing in the rule book about any 'continuous action' and the run does not count.

My question is this. What is this "continuous action" play business? I heard another coach refer to this during another game (not mine) and I was wondering what the heck the coaches were talking about.