So colour me skeptical. As they say, extraordinary claims require extraordinary evidence, and this theory is making several extraordinary claims:
1) A hybridization event indeed occurred in the relatively recent genetic history of homo sapiens (rather than the unusual anatomic features being produced some other way).
2) The hybridization was with a close relative of pigs (rather than another family that has some similar characteristics, or multiple hybridizations that together gave us the unusual characteristics).
3) The hybridization marks the point at which hominids split from the other primates (rather than occurring later in one branch of the hominid family tree).
4) That the genes introduced by hybridization gives hominids their unique characteristics (rather than being inconsequential).
In return, the theory presents evidence (anatomic oddities and low fertility) that I would characterize as "interesting" and perhaps "worthy of further study", but certainly not extraordinary. For this to be plausible, there needs to be a second avenue of evidence, one not based on anatomic similarities...
That second avenue could be genetic, but they specifically dismiss it, presupposing a mechanism, backcrossing, that leaves little genetic evidence that it occurred. Now, I'm no geneticist, but that sounds a bit fishy to me.