I would think you would only have a case if the elders had some knowledge of his behavior prior to his harming you. Otherwise, it's not something the Watchtower could have prevented. Conti won because the elders knew about her abuser, as he had been accused in a prior case, but they still allowed him to go out door to door with her.
If the scumbag that molested you had later gone on to molest someone else, then they might have a case, depending on the circumstances. But you should contact an attorney to be sure, laws vary from place to place.