Obstruction or interference

[akalsey]

R2 going on the pitch. Ball hit behind the runner to F6 playing deep. F5 breaking toward the ball, but has no chance at the play. R2 looking over his shoulder to see if the ball leaves the infield, F5 looking out toward F6.

The collide about 6 feet from third base. Runner makes it easily to third (no fielder is there), has no chance to go home because F6 fields the ball cleanly.

Under LL or OBR this sounds like obstruction, but no bases awarded.