A primate/primitive ungulate don't need to produce a hybrid or fertile offspring since obviously aliens mixed chimpanzee and pig DNA to create us, a race of slaves to mine gold for them.
They also removed our ability to synthesize vitamin C in the process as a method of control.
Is there some evidence that the hairless trait was the result of human selection and no hairless varieties existed before human selection?
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.
That said, this is way, way too far fetched. Proposing that a primate and a primitive ungulate can produce an hybrid is already a big stretch, let alone producing a fertile one. Then, he supports his claim by refusing the genetics, and hand picks morphology aspects from the suinae that confirm his theory.
What did it for me was the "naked skin" evidence though. It's the human-selected, domestic pig that is hairless.