Was DanHarmon.com ever a legit Dan Harmon site? I can't say. Certainly it has Dan's famous attitude splashed about like territorial piss markings. If Dan was running it, he hardly used it. The last time it functioned normally was late 2011:
http://web.archive.org/web/20110827032344/http://danharmon.com/Either somebody else owned the domain all this time and set up a fake DH site or Dan was happy to let the neglected domain lapse.
As far as I know, the real Dan Harmon blogs solely at:
http://danharmon.tumblr.com/