Wild boar are very trusting creatures, and will come up to you if you sit in the brush and call gently 'here, piggy, here piggy". you can then stick 'em when they are not looking.
NOT
however, I imagine he did it with a variation on the following.
Back home in Alabama, they use dogs, normally dressed heavily in armour to cover their vitals and prevent goreing, the dogs chase down and hold the pig long enough for the hunter to come in and finish it with a thrust behind the front leg into the heart, of course if the dogs have a bad hold, and it slips, the frail human can get sliced by their tusks, as can the dogs. occupational hazard. (dan, now you know why a long knife is a good thing, and why european wild boar hunters use boar spears or hunting swords) wild boar sausages! Mmmmm Good!