I first encountered him in a thread about Pleistocene mass extinctions and whether they were due to hunting. He had read some of the scientific literature from decades ago, and quoted those articles. I cited some more recent literature that had a broader view.
Ever after that, when someone posted about Pleistocene extinctions, he would pop in and make exactly the same arguments as before. Sometimes he would cite the article I had originally cited to him as if I might not have seen it to refute me, but completely misunderstanding the point.
Eventually I just gave up. I would just state my points and that I wouldn’t discuss it with him anymore.
He’s also extremely credulous. Here he persistently defends a crackpot “translator” of the Voynich Manuscript despite knowing nothing about the subject.
He also has never learned to quote properly. You can recognize his posts by extremely long quotations in italics instead of a quote box which are usually irrelevant.