Runner Interference after Scoring?

 
With no outs and runners on third base (R3) and second base (R2), the batter (B1) singles safely to right field.
 
R3 heads home, slides, and safely scores easily. After scoring, R3 stands at home plate waving R2 home. The right fielder throws home to try to retire R2. However, the catcher and R3 get tangled up as the catcher is fielding the throw from the right fielder. R2 is safe at home. In all the action/confusion at home plate, B1 ends up at third base. How many runs score? Any outs on the play? What about B1?
 
Call
A retired runner is a player on offense who has been put out by the defense or who has scored -- but has remained in live-ball territory. A retired runner (such as a batter, batter-runner, or runner) may not interfere with play while the ball is live.
 
In the situation below, R3 is a retired runner, but he interfered with the catcher's attempt to retire R2. Since R3 had already scored, his run counts, but his teammate (R2) is out due to R3's interference. B1 must return to the base that he last acquired at the time of the interference.