There is a story in Brachos where R' Ada bar Ahava ripped a Karbalta (a red non-tznius garment) off a woman, and then discovered that she was not Jewish. He then was fined for that act 400 zuz. He asked this non-Jewish woman "What is your name" and she said "Masun". He then said "Masun Masun you are worth 400 zuz".
From the fact that he went to court and had to pay the money only after it was discovered that she was not Jewish, implies that had she been Jewish, he wouldn't have to pay. Moreover, he seemed upset that he had to pay, which would be surprising if he would have to pay her if she was Jewish.
Does this story imply that one who damages someone to prevent them from doing an aveira is not obligated to pay for damages?