Have you thought maybe of challenging this person? You don't need to do so aggressively but instead ask for facts/links - you're entitled to do that. Other than that you can message the person privately and express your concern, you don't have to expect them to do anything but sometimes honest feedback can be enough to encourage people to want to change. Other than that you might have to concede that some parts of PC will be off limits to you for a period of time. PC can't always be what we want it to be - it's just not reasonable to expect otherwise. I find attendance and posting frequency goes in waves - a member who posts a lot at the moment may not do in the upcoming weeks. Not everyone can be here all the time and post as such - maybe it's easier to monitor when they're posting less and jump in only when you're sure you'll be clear of them for a while. I hope you find a solution soon.