5. Prohibits member states from preventing the press from reporting on any story without a compelling safety or security reason, to which a prohibition on reporting would be the easiest or most effective response; The State cannot use the safety or security reason exception to prevent the press from reporting on this matters:
a) Violations of human rights
b) Crimes against humanity
c) Illegal activities - with regard to national or international law - involving state officials
“The issue is that such blanket prohibitions could very quickly become counterproductive. If the government of a member nation is trying to gather more evidence before arresting a corrupt official, then a newspaper reporting on said corruption before any evidence has been gathered would be very unhelpful.”
You are right on the c) point. Another formulation could be:
"c) Illegal activities - with regard to national or international law - involving state officials, except in the case in which the journalistic activity could cause damage to the conduct of investigations by the judiciary."