His argument is that the domestic pig and the wild boar are not the same animal, which is pretty obvious. Then, he claims we don't know where the domestic pig came from, and that a common ancestor could be hairless.

That is still a pretty weak argument considering from all suinae, the domestic pig is the only hairless, and for his hypothesis to work, hairlessness would have to be a dominant trait (otherwise, logic says we should be hairy like a chimp).

I'm no geneticist or anything like that, but there are some pretty (big) holes that he doesn't address and attributes to ignorance. You can't make an hypothesis plausible by claiming about what you do NOT known - you have to show positive correlation, not absence of negative correlation.