> I don't say this because I think we should just take the venerable professor's word for it, but because accusations in general, if they're vague enough, are impossible to defend against.

I have my doubts on this, because widespread use of sealed recommendation letters already make blackballing/indefensible accusations sort of the norm in academia, but in this case biased against students. When a student gets the courage to complain in the open, I tend to see it as making the playing field more even.

I think a Glassdoor-like site, but for academic advisors and research groups would be quite popular.