[Andy]

I think that the umpire needs to make a judgement call here. Was the catcher actually going to throw the ball when it was knocked from her hand? In order for me to call interference on the batter, the catcher has to make a throw. If I think the catcher is not going to throw, just hold the ball up in a throwing motion to "encourage" the runners to return to their bases, I'm not likely to call interference. Let me say that if the runners try to advance after seeing the ball knocked away from the catcher, then I've got an interference call. I agree that if interference is called in this situation, the batter is out and the runners return to their previous bases.

Ok, let me know if I'm off base here in my interpretation.