Batter Interference?

[Dougster45]

Two outs. B4 at the plate, R3 on 3rd base. Passed ball. R3 breaks for home. B4 steps bckwards towards 3rd base dugout and out of box so pitcher can can make a play at home plate. Ball has rolled toward 3rd base side of backstop. Catcher recovers, but instead of turning and making a good throw, flips the ball behind him toward home plate. Ball hits batter in the back. Ball had a good chance of being caught by pitcher before the runner crosses home plate. Runner crosses the plate. What's the call? What is the rule reference?

Thanks