I'm going to play devil's advocate.
In order for there to be a play you need a ball and a runner. With the runner going back to third, you don't have a runner at the plate, therefore no play, right? No Play, no interference. Now if the runner broke for the plate and the OP happened then you would have INT because then you have a ball and a runner, therefore you have a play. In your What if scenario, you have a runner who advances and ball, therefore based on the action, you could have INT.
Please correct me if I'm wrong here.