The only help I can give you, since the wonderful State government of N. Carolina has decided to simply leave the monkey of obeying its regulations on your backs, is this:
On hogs that have gone wild, it takes only a few generations for the 2 toed structure of the hooves to close, or " fuse together " and become one hoof, like the Russian Blue wild boar hoof is. The wilder they seem to get, the darker they seem to get, too. Feral hogs seem to keep their two tone colors, or light tan color for a generation or two after they break from captivity.
Check the tracks left by the hog you are stalking, and then check the colors. If the hog is very dark, you should err on the side of caution, and let him go. Just report the location to the Game Department so they can verify and update their maps as to where " wild boar" are located.
Finally, it is not uncommon to find feral hogs feeding and living with wild hogs. Again, the changes in the hooves is the most readily visible clue as to whether the hog is now wild( and may be protected) with the color being second- a very distant second place. Talk to locals about the colors on feral hogs, if you are hunting an area where you are not familiar with the local stock.
Its a darn shame that hog farmers don't collect and return hogs that get out of enclosures, but those operations have gotten so big these days, it may be weeks or months before a hog is recognized as missing, and no possible way to know then where it went or what happened to it. Over years, the problems compounds. I would think the Government would encourage Hunters to go out and shoot feral hogs, during those limited wild boar seasons, by selling much cheaper permits, so many more people would be out reducing the populations of hogs, wild or feral. Instead of charging, say, $20 for a wild boar hunting permit, and selling maybe 1000 of them, why not sell 20,000 permits at #2.00? You wuold double your money, still reduce the wild boar population, and all those hunters would surely have an impact on the feral hog population, no?