I'm in favor of the "buy and carry what you want/are comfortable with" side of things.....you know that old thing about a 22 that's with you or a .45 left in the safe at home.
If the person in question is highly recoil sensitive or something and simply will not carry a handgun in a larger caliber, then a 22Mag doesn't sound like such a bad idea to me. I know a little 85 year old great grandma who can't handle a .380 or 9mm but can very comfortably carry and shoot her .25acp Beretta.
I don't know anyone that's been shot by a 22Mag, but a few people I know who've been shot by .22lr definitely won't be telling you about the lack of stopping power.
---Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.---
---Enlightenment is the ability to take infinite pains---