The Tara Knight situation is pretty bad.
Obviously it's awful that she faked a letter from the FBI telling her to Stop Writing About Transfeminism, just for clout/clicks. I'm glad she admitted to it in pretty quick order so things have a chance of settling down and other trans people writing about trans theory online can feel more at ease.
Unfortunately, that's probably not going to happen, because this is now a Discourse Nexus and everyone is primed to shout about it a lot.
At least one 'journalist' is apparently trawling for people with 'stories' about Tara's alleged interpersonal wrongdoings to come forward (to be clear, this is hostile muckraking that benefits nobody), and it's probably only going to get more vile over the next few weeks.
What happened is already clearly documented public knowledge. That should be enough!
I think a hard and annoying truth to truly internalise is that people in marginalised communities are not immune from the pressures that make people act unpleasantly, selfishly, or even scammy. In fact, they feel these pressures more than non-marginalised groups, by definition.
Nobody has insight into other people's minds, so the exact motivations for this sort of stuff are going to remain opaque. No amount of additional blame or harassment (or gloating, or muckraking) will move the community towards a better understanding of what happened, why, or of the person behind it.
In the end, 'scammers' or 'grifters' are not a separate class of people who have an inherent advantage over everyone else. Sometimes, people you are in community with are going to lie or pull some shit in order to benefit themselves.
Treating anyone who pulls this sort of stunt like a perpetual target for 'punching up' discourse (or even just harassment) isn't reasonable. It doesn't solve anything. It doesn't work to alleviate the conditions that make people consider harmful, selfish behaviour.
If you're so disappointed and angry with someone that you can't trust a single thing they say anymore, then the best and healthiest option for you, them, and the community at large is to disengage from them completely. Don't start whisper campaigns, or dig up more 'proof' of various wrongs. That will have zero positive impact.