Well not to double post In a thread but even without a great shot placement a 22 will kill, my uncle was murdered with one 10 years ago. A 22 will end a life the question you should be asking is will a 22 stop a threat long enough for me to get away from the threat. A 22 will take longer to stop a threat then a 44mag either by milliseconds, seconds, or minutes. How long is the fight In your heart to survive against an armed threat and how much are you willing to train. If someone who has a 45 is never willing to train are they still better off then someone with a 22 who practices gun retention, mag changes, rapid action drills , close firing, distance firing. As per personal experience a 22 will drop a man the real question is how much training should You commit to defending my life.
(Not sure but please no sorry for your loss **** happens don't dwell o. You losses but enjoy your gifts)