Please see post 51. Unless you have a Metal backstop surrounding the entirety of your home (both windows and walls), using your argument, a firearm sholuld never be used inside the home.
I've seen this many times. Rob Pincus knows his subject. Maybe you should have watched it to the end. The birdshot did not penetrate thru the second layer of sheetrock, so when you add insulation, brick (possibly), then the exterior of your neighbors house, it's a pretty safe round to use by comparison. Nothing is 100% safe, but like I said before, the guy in this story screwed up because his round hit a neighbors house. The person pulling the trigger is always responsible for every single round fired...no excuses.