He shouldn't confuse other ppl it's like he doesn't care he's made problems. You're trying to protect random ppl from getting wrong info so it's upright concern but you can't stop him in reddit or bitcointalk. You can't use ignore button because you don't want someone's lies turned into facts & you can't reply to his posts because you'll provide more opportunity to misbehave. It isn't easy choice if you stop intercepting him but it's his freedom of speech so he won't stop.
You can use one nice remedy called ignore button, than just stop reading all his posts and stop responding to him.
Works really good at turning lies into accepted facts. I've had multiple journalists who printed outright falsehoods that I complained to point to some (usually reddit) thread and say "no one disagreed" -- though on reddit it's extra sweet since logged out users don't see neg rated comments, so in one instance *I'd* actually thoroughly debunked the post and reddit helpfully hid it from the person who needed it most.
In any case, I don't mean to argue that anyone needs to waste their time on idiots. But ignore isn't a magic fix-all solution either and has in its own way cause a tremendous amount of harm, but sure it saves the poster from wasting their time. It can be easy to forget though that the most readers of many posts over the long run won't be regulars or thread participants, but randos doing research or people that landed in from a search engine.
It occurs to me that keeping a counter on what percentage of posters in the thread are ignoring a poster could help, but that's getting offtopic.