There does come a point at which unwillingness to learn what is going on crosses the line between truth and falsehood. The libel standard for public figures, after all, speaks not about knowingly false but of "reckless disregard" for whether what is being said is true or false.
In this case the reckless disregard, the intellectual laziness, the unwillingness to learn *anything* rises to an extraordinarily high level. Note that the particular case at issue is not whether HIV has been isolated but whether there is any "evidence" that HIV has been isolated. I've seen X-ray photographs of crystals of HIV. They are evidence that it has been isolated.
More damage is done to the language by *not* calling Chris a liar than by calling him a liar. And I am happy to join those who do so.
Brad DeLong