Playing in a tournament, I missed a short par putt and went to tap in the comeback putt without marking it. As I addressed the putt, (Soled the putter about 1/2 inch behind the ball, the ball rolled backwards and struck my putter! The question is which rules apply here and what is the appropriate penalty. Does the ball get replaced? Are there two penalties, one for the ball moving and one for the ball striking my equipment? After I see the responses, I will let you know what the ruling was.

Ok. Assuming you have taken your stance and grounded your club behind the ball, the penalty would be 1 stroke and the ball would need to be replaced. There is no addition penalty for touching the ball with your club. Rule 19-2 (ball in motion deflected or stopped) does not apply in these circumstances. See decision 18-2b/12 for guidance. How did your ruling compare?

You have it correct. My score was double bogey 6 and the ball was replaced. I did have a co-competitor indicate that both penalties applied and thought I may have had an 7 or a DQ since I replaced the ball before putting. Of course I did not sign the card until after the ruling.

Assuming that the ball did actually come to rest before you addressed it, jaskanski and the ruling you received during the tournament were indeed correct.