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.
If i am not mistakenly i have came across where someone passes wrong information and still act proves to be right which i knew too well such information was wrong but what do i do, i don't have to go reacts negatively but it's left for those who are listening or reading the information to make additional research for themselves to know if that information is right or not. What matters most is public composure, at least respecting each others choice is one of the best thing to keep and stay clear. So the best is he write or say that people should sources for additional information from other various writers or authors before accepting fully into what such person is passing through, because it is true that on the internet when someone are passing wrong information we can't stop and even if we ignore them it's not also helping matter because other people or newbies would still come across such information to start using them. So the best is, if any information found that is not correct then it should be reported and mod/admin should carefully evaluate such post before having deleted entirely, but in terms of reddit downvote could be more appreciable to factor out how low such comment and post could be.