With R1 on first and 2 outs the runner attempts to steal.  The batter interferes with the catcher making a throw and the runner reaches 2nd successfully.

Umpire Ruling: Batter Interference/Delayed Dead Ball.  Ignore if runner is thrown out.
Penalty:Batter is out, all runners must return to previous base.
Rule Book: Delayed Dead Ball Chart/Rule 5-1-2a