I think the state's own findings are quite sufficient. The trick is to incentivize their use without unduly obstructing other operations of equal importance.
The state has already satisfied itself sufficiently to reverse a murder conviction. If the investigation that led to that course of action was causally descended from an article written by a journalist - what of it?
If you believe that the actions taken by the state up to this point were unwarranted, say so explicitly. Otherwise, please recognize that I am not talking about journalists here.