I started typing something, then realized it was based on someone's claim in a forum discussion and I hadn't bothered trying to verify it.
It turns out that the information was exaggerated in such a way that, had I not bothered verifying, I would have updated much more strongly in favor of the efficacy of an organization of which he was a member. I got suspicious when Google turned up nothing interesting, so I checked the web site of said organization, which included a link to a press release regarding the subject.
Based on this and other things I've read, I conclude that this organization tends to have poor epistemic rationality skills overall (I haven't tested large groups of members; I'm comparing the few individual samples I've seen to organization policies and strategies), but the reports that they publish aren't as biased as I would expect if this were hopelessly pervasive.
(On the off chance that said person reads this and suspects that he is the subject, remember that I almost did the exact same thing, and I'm not affiliated with said organization in any way. Is there LW discussion on the tendency to trust most everything people say?)
It turns out that the information was exaggerated in such a way that, had I not bothered verifying, I would have updated much more strongly in favor of the efficacy of an organization of which he was a member.
I initially misread this as saying you were impressed with his persuasive skill and strongly tempted to update on the organization's effectiveness based on that.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.