[greymule]

Foul ball, nobody out, runners return (same as in OBR). Just as you call the batter out on the IFR and then negate the call if the ball becomes foul. Just as you ignore the OBS if BR who has hit a long fly is obstructed while rounding 1B before the ball is caught.

Of course, anything is possible in a code that (1) permits a BR who hits a bases-loaded, no-out pop toward 1B to collide intentionally with F3 to break up a double play, and (2) still allows the run to score if the runner from 3B had touched home before the collision.

So I offer another rule change: "If the BR has not touched 1B at the time of the interference, each runner shall return to the base legally occupied at the time of the pitch."