With no outs, the runner on second base (R2) is stealing on the pitch, and the batter (B1) has a 1-1 count. The catcher receives the pitch and then attempts to throw to third base to retire the stealing R2. The batter interferes with the catcher's throw and the catcher's throw hops past the third baseman. R2 rounds third base, but the outfielder retrieves the bad throw from the catcher, throws home and R2 is tagged out. 

 

Who is out and what do the umpires do now?