You have it backwards. 8 out of 10 can and do excerise restraint. The other 2 that don't suffer the consequences through the legal system.
So, the two should be the measure for the other 8?
The law is quite clear in the meaning of self defense. There are enough laws on the books now regarding this topic. The event is looked at, and charges, of any,are brought up.
I am a peaceful person. I have a high tolerance for all type of BS. If someone comes to my house with bad intentions, my family and I will not cowar in a corner. We will defend ourselves.