More boring stuff on liability.
There are two different types of liability the average gun owner faces; negligent conduct and intentional acts. Each liability issue is somewhat different, and has both civil and criminal ramifications.
Negligent conduct pretty much equals stupid conduct. Negligent conduct is a c- in gun handling, which causes an injury. You dropped your pistol while walking on the range, it discharged, and shot the leg off the 6 year old in the next firing point, or you stored your locked and cocked 1911a1 in a range bag, and when you tried to remove it from the car, it discharged, killing your next door neighbor. That sort of stuff. Almost everyone has discovered a loaded firearm that they thought was unloaded. How many have had a AD either at the range, at home or in the cleaning area. The next big area of gun owner liability may be stolen guns. Under very particular circumstances, you can be sued because your stolen car was in an accident, and I suspect that you will be sued if a thief steals your unsecured gun from your home, and hurts someone with it. You'll probably win, but you'll be sued.
In negligence cases, you'll probably have the benefit of your homeowners insurance, and the issue will be if you were reasonable in handling, storing, shooting the gun. This is where the modifications on your gun will be relevant. Did you have a 1.5# trigger pull on your gun with a pinned grip safety, which allowed it go off when dropped. Would the movement in the bag caused the discharge if the grip safety had not been pinned. A good plaintiff's attorney will investigate the cost of the pistol and use that for damages if possible or compare it to the cost of a safe in which to store the weapon to make the jury mad at you. After all, why do you need a $2,000 blaster when a $150 gun will do just fine. But, as said before, in a civil case, the chances of a settlement are great, and the insurance company will probably have to pay as you didn't mean to intentionally hurt the plaintiff. You might lose money if the injury is great and your insurance limits are low. The plaintiff's attorney might require you to forfeit the lot in the mountains for extra compensation. You might even have criminal liability, as there is such a thing as negligent homicide.
Of course, there is stupid stuff, like shooting birds in the next door neighbor's yard, seeing the splash of water when you shoot your suppressed Ruger Mark II from the roof of your house into the backyard pool late one night or clearing a suppressed weapon late one night and discovering it loaded. At that time, the sound of tinkling glass can be as frightening as sound as there is. Trying to shoot a beer can thrown into the air immediately after finishing one seems a routine sport here in the desert. All these are stupid. But, until you hurt someone or damage property, there can be no civil liability, even though the local cops would want to talk to you about this sort of stuff. I believe you deserve what you get is these sorts of situations, as you've been careless with something that can injure unless you take some care. In Arizona, you'd be prosecuted for any of these events.
But when you purposefully level the front sight on another human with the intent to destroy that person or be destroyed yourself, then you are risking everything. Failure to understand your situation can cause you to lose it all - your freedom, all you own, your family or even your life. As everyone has said, here's where your training comes into play, and the circumstance of your weapon plays little part, except it had better work. You'll be sued even with a valid shooting, just as the police are routinely sued for money damages for a very valid shootings. You will probably not have the benefit of insurance coverage, so you'll have to finance the litigation by yourself. Costly, very costly. And, the more you try to prove your qualifications, the more a jury would think you just might be looking to exercise your training, rather than defending yourself. It will harder for a jury to understand or believe that you are as well or even better qualified to shoot that the police. Damages would be interesting in this situation, as you'd be faced with the claim that the deceased, (hopefully) routinely supported his poor family through the profit from his life of crime, and but for your interference, he'd still be able to continue with the crime to support his family.
Advice? I join Bruce. He said it best. Don't say a word to anyone, ever, until your with your lawyer in a closed room.
BTW, Bruce, that's a absolutely great thought about bringing in all the criminals in these blanket gun manfacturing lawsuits.