Two occasions. No hard use, not sure if really "life-saving", but I wouldn't like to find out what would have happened if I didn't have THE knife on me.
True accounts of true events, that I can promise.
None of these happened in the States. Or it wouldn't be a knife that I pulled out.
1,
Was going to my car in the lot of the gated community I lived back then. Saw the gate security along with a mid-aged lady walking towards and shouting at an edgy-looking guy stumbling around different vehicles.
Stopped for a moment out of curiosity. Turns out the guy was putting those shady loan cards in cars' windows in this parking lot, and that resident lady reported to the security.
Of course I teamed up with them to shout the guy away, however the next thing I saw, he pulled out something looking like a 26sp and started quickly walking towards us. We were like only 10 feet away and the security guy was shocked frozen and did absolutely nothing, didn't even run.
So I pulled out and launched my Makora II. (Later I found the security had nothing but a flashlight on him, which I still find hard to believe. Firearms are strictly illegal in that country but he could at least carry an ASP baton or a Taser?)
Guy immediately stopped. We stood there for like 5 seconds (felt like forever. only found out to be seconds when reviewing security footages afterwards.) Then he turned around and walked away, shouting threats that I later found out to be not-so-empty.
Two days later the gate guard house was smashed and partially burned at mid-night, while the security personnel was on patrol. A week later the perpetrator (that same guy) was arrested. Turned out guy's a wanted felon with multiple drug and assault warrants on him. They managed to arrest him so quickly because the community I lived was relatively well-off and had hundreds of CCTVs all over the surrounding blocks.
2,
Cold winter, was waiting for friends in the lounge area of a Japanese Nabe pot (you cook everything in a large clay pot on your table) restaurant. Was looking forward to a warm dinner.
A rather drunk guy was guiding his friends to pull out their car by the front door of that restaurant. Problem was: he was standing in the door way and keeping the doors open, letting all the 28F "breeze" in my face.
I asked the manager to ask him to close the door, he refused. Then I joined the manager to ask him to be respectful to other customers and close the door, (of course I didn't ask as polite as the manager), he was pissed.
He grabbed one of those tall standing ash-tray-thing by the thinner part, holding it like a baseball bat, and walked towards me and the manager.
I pulled out and launched my Makora II. And asked as calm as I could WTF does he want.
He stood there a bit shocked, then dropped the ashtray thing, then hopped in his friends' car, all the while shouting some empty threats.
The manager was thankful for my action and offered me to jump the line and a sofa table and discounts on that dinner. However I left immediately, fearing for those threats being not empty, and only enjoyed those offers a few weeks later. Turns out those threats were empty, and no repercussion happened at that business.