Full disclosure, I tend to agree with FlyingSquid in the instance that kicked all of this off. I don't have a clear opinion of them as a mod, but personally I wish the LW mods would do a lot more about the "Kamala Harris = Hitler" type of misinformation that gets a free pass on a lot of LW.
FlyingSquid comes across as perfectly reasonable in this conversation. Their arguments that another mod thanked them for reporting stuff, that it's two reports over the course of ~~two weeks~~ a week which is hardly excessive, and then when the two people couldn't see eye to eye, they said they just wouldn't flag anything, sounds all perfectly reasonable and sensible. For some reason that wasn't okay, and the conversation got personal, with Blackbeard constantly posting these aggrieved attacks about how FlyingSquid was being childish if he didn't continue to report things in someone else's community occasionally, but never anything that the mods there thought was not worthy of removal. And then petulantly refusing to say something along the lines of, "Of course you're welcome to post there if you want" when asked repeatedly if it was okay for them to just post and participate still.
I haven't seen any Discord harassment, so maybe I missed something, but if this is what gets posted as justification for why FlyingSquid is a terrible moderator, I suspect that the "harassment" is more of the same. Maybe it's along the lines of "not saying exactly what I want you to say, or having conversation with other people where you say things I don't want you to say." People are allowed to disagree with each other over what is misinformation, or choose not to report content in someone else's community if they get some hostile responses when they do. Trying to order someone else around and then getting personally insulting with them when they politely tell you "No, I don't agree with how you see it," is ridiculous.
Edit: I don't know why I said two weeks, it was one week.