If an advisor at the university is doing misconduct, the grad student should consult a lawyer.
The lawyer doesn't yet have to be facing the university, but you need advice.
All the anecdata I've heard is that elements of the university will be adversarial and underhanded in response to legitimate and constructive raising of something that elements would rather be buried.
The sketchy people will want to make the student go away, ideally an international student who can be sent back to their country, or otherwise neutralized. It's harder to come back from that. Having a lawyer from the start helps avoid being neutralized.
Some universities might be more or less sociopathic than others, and a rare school might be genuinely warm and fuzzy and benevolent in every aspect. But I strongly recommend starting by assuming that, for some elements of the university, it's much like a big for-profit corporation in behavior, only one accustomed to better PR and less accountability.
(I have a fondness for university ideals, and there are particular ones, and especially particular professors, who I respect highly. But there's realistic advice some people really need to hear, if they don't want to throw away brilliant careers in which they've invested their lives thus far.)