After you protect yourself, the irresponsible one gets to file a lawsuit and try to take your house.
I must admit, the best use for pepper spray (for non-LEO folks) in my opinion is for anti-dog situations. You have to feel sorry for the dog afterward (because its behavior is due to OWNER failure, not dog failure) but it doesn't kill the dog, and works like a charm. (Dogs don't know to dodge, close their eyes, or close their mouth.)
When on walks like that, I strongly suggest having a medium-sized canister of high-quality, high-volume pepper spray. Versus dogs, (IMO) it is actually much more effective than a firearm, with MUCH less nonsense afterwards.
"
You killed my dog!" "It was attacking me!" "
I'm taking you to court, you dog-killer! Why do you even CARRY a gun in this nice neighborhood!" etc...
versus
"
What did you do to my dog?! "It attacked us. It was just pepper spray, he'll be fine in a little while. We are, however, reporting this attack to the police, since you didn't control your dog." "
But, but, he was just..."