True, a shotgun is not the sort of thing you'd carry for personal defense outside your own property, but for home defense, a 12-gauge pump-action is as good as anything, and better than most -- especially when, as mentioned in the article, you have surveillance cameras at the approaches, so you can see any unwanted guests coming with enough time to prepare for their arrival.
The best type of firearm to have for personal defense is the one you have on you, not in your gun safe. The 12-gauge is only beneficial if you're going to carry it with you from room to room, keeping it at your side at all times.. The time between hearing someone kick in your door to being on you is just a few seconds, there's no time to open a safe. So in this type of scenario the 12-gauge isn't bad, but I'd probably still prefer a pistol on an over the waist band or shoulder holster. When you don't need to conceal it's not that difficult to carry around a full sized pistol in any reasonable defense caliber. It appears that this guy is toting his shotgun with him though, so I guess there's that.
