[nickrego]

The R2 did not Intentionally let the ball hit him, so there was NO Interference.

R2 is out for being hit by a fair batted ball, R3 returns, R1 advances to 2nd due to being forced by BR being awarded 1st.

All this confusion comes from how silly this rule is. It would be much simpler if it was, for all cases other than (intentional) Interference; BR out, all runners return.