In an unofficiated match, I think playing a let would be the fair and right thing to do. However, if I was a roving or chair umpire, I would have given the point to the receiver. Since the player who called out was where she was supposed to be, that is, ON HER COURT, she really didn't cause a hindrance. Now if she had been running over near or on the court where the player was returning serve, I would have called a let. Take this example and maybe it helps clarify the situation....let's say Scott is playing on the ad side and runs onto the adjacent court to chase down a wicked angle. In doing so he runs into a player on that court. He asks for a let due to this interference (hindrance.) Welllll, he will be denied because that other player was where he was supposed to be (he was on his own court.) Now if that player had run onto Scott's court and hindered him, then that is a let since Scott was on the court that he was supposed to be on.