You are missing the point. "if you can manage a few head shots"? you don't understand incapacitation, and the difference in killing. a justified incapacitation is far better than killing someone. And you will be accountable for every round fired and your reason for doing so.
The point of "a few head shots" was simply that if you genuinely perceive your life to be in danger, you may not stop the attack with one (hopefully) well-placed shot, even to the head, esp. with a low-powered round like a .22. But I agree that I may have put it rather badly.
This is why I shake my head when I read of a police shooting with several rounds fired and someone comments, "Why didn't they just shoot him in the leg"?, the answer being that in SHTF situation, such precision is rarely possible, even though most of us would agree that it would be a far better outcome- minimal force used to achieve the required goal. And indeed, I think I stated in an earlier post that the intent is not to kill, but to stop the threat.
I am often appalled by the comments on the 1911 or S&W Forum where someone posts a case of someone defending themselves and people chime in with stuff like, "The little m***f***s got what they deserved", "I love a happy ending", etc. Mind you, we don't live in communities with the levels of seething personal violence that some of those folks do, like "The Jungle" in Seattle where three kids, age 13, 15 & 17, recently murdered someone. Maybe we'd think differently if we did.
Agreed, we would be accountable for every round. And some clever defence lawyer might well try to argue that "if you only felt it necessary to slightly wound my client with a single round, I suggest that he wasn't in fact posing a deadly threat." Damned if you do, damned if you don't. Look at the Ian Thompson case- a suitably restrained reaction to a potentially very serious act (warning round with a .38 fired at 2 guys torching his garage). Not charged with illegal discharge/irresponsible use of a restricted weapon, as one might expect- they eventually pinned "unsafe storage" on him! All eventually dismissed, after a couple of years' wrangling in court and tens of thousands of dollars in legal fees which he'll never recover.
Fortunately few, if any, of us are ever likely to find out the hard way if our pet theories are correct or not. I'm happy with that.