The batter is out for running outside the lane and since he also
interfered with the throw home, the interference is enforced on R3, who
is also out. Inning over is my guess. The ball is not dead when it hits the runner since it was not a pitched ball, so R3 would not have to be sent back, but he can't be safe at home due to the interference either. I would think this would be the same call as when R1 interferes with a throw from second when attempting to turn the DP.
Oh well, wrong again. What's new