That's unfortunately all too common of a story. And with the way peer review works - where the leaders of any niche topic are the ones who will be asked to peer

That's unfortunately all too common of a story. And with the way peer review works - where the leaders of any niche topic are the ones who will be asked to peer review articles in the same area - the system makes it very easy for an established professor to shoot down dissenting voices. Now, sure, if you can prove that there was deliberate misconduct on the part of the PI, then you can go through channels and hopefully get an investigation opened. There was an article on HN recently (linked in another comment here) where this happened/is happening with Alzheimer's research. But it's often not so clear cut, as you've pointed out - you leave enough room for ambiguity, then "apologize" and retract the paper. There's no (significant) negative consequences for the retraction if you're already an established leader of your field (and you can still use your influence over the peer review process to shape the field to continue favoring your research). Meanwhile, the accuser is all but guaranteed to be blacklisted from their field for the same reasons - and if they don't have tenure yet, then game over, hope you had a backup career in mind. The current incentives in academic research are broken. Sometimes I wonder if the tenure system is partly to blame - does it go too far in creating these protected positions of power that can be abused? Then again, tenure exists for a very good reason - to protect dissenting voices by being pushed out by these same forces. It seems more and more however that tenure is no longer sufficient to protect against this (or maybe it never was), and we need broader reform of the peer review system in order to foster healthy and open discussion in the research community.