Sharkbite hit the nail on the head. And Evil Monkey, while I agree with your premise that most arguments about handgun "stopping power" and "terminal performance" are pointless and ridiculous, you're using the exact same unscientific reasoning that those who say, "hurr durr 45 is more power hurr durr" use.
One example -- like what happened in this video -- can't make or break a scientific argument. If you're going to use this video to prove your argument, that means you have to accept others' arguments using the same kind of evidence. If someone produces a video that shows someone dropping like a rock after being shot once with a .45, does that prove that a .45 will always drop someone immediately? Of course not, just as your video doesn't prove that terminal performance shouldn't be argued about. Someone who still believes the bunk that there's a large difference in defensive handgun caliber effectiveness will just point out that this video is an outlier. Or they'll say it's obvious he was using an under-powered handgun caliber.
Again, I don't disagree with your overall premiss, I'm just playing Devil's Advocate to point out the flaws in your argument.