Let's suppose some students gather every evening in a student dormitory and make loud noise till late night by playing guitar, talking, singing, laughing, etc., and a female student from the same dormitory reports them to the dean after unsuccessful attempts to resolve the issue by talking directly with the students. One night the dean comes to the dormitory to verify the complaint and witnesses everything himself. Those students are now in deep trouble and are facing a university hearing, with some of them being now in real danger of getting kicked out of the university in view of some previous issues and poor academic records. You want to praise the girl for blowing the whistle. What will you call her in Russian?
I know a few Russian words synonymous to whistleblower, but they seem to be highly negative - ябеда, доносчик, стукач.
I also know some rather neutral words such as информатор and осведомитель, but these words are too generic, meaning informer rather than whistleblower, and still lack a positive connotation.
Is there a positive Russian word for a person who voluntarily and on his or her own initiative reports someone to authorities in a one-off report, having not been recruited as an informer beforehand?