The RTPJ doesn't control morality, it controls theory of mind. This is known and the study admits it (though the BBC doesn't).

All this shows is that moral judgments that require considering people's mental states call the theory of mind function, which is predictable. If you can't think about someone's beliefs at all, you can't use them as a mitigating factor in a moral judgment.

If you gave someone a stroke and caused hemineglect, they'd stop condemning immoral actions that happened on one side of the visual field, but that wouldn't mean you'd discovered something interesting about their morality.

The study gets this exactly right: "Our hypothesis therefore is that TMS to the RTPJ affects an input to moral judgment (i.e., belief information) but not the process of moral judgment per se."