Continuing with how the state constitutional right to self-defense has indeed been asserted -- sometimes successfully -- in various kinds of cases:

Criminal Law: A few cases have used state constitutional self-defense rights as guides for determining the scope of permissible self-defense in criminal cases. For instance, Ohio courts relied on the Ohio “defending life” provision to recognize an exception to bans on felons’ possession of firearms when the felon picks up a gun to stave off an imminent threat. Likewise, a California court relied on the California provision to clarify the longstanding principle that self-defense is unavailable when the defender is the one who started a deadly fight, a principle that has sometimes been imprecisely cast as an exception for cases of “mortal combat.” The jury had been instructed -- in the language of the applicable statute -- that “a person claiming [self-defense] if he were the assailant or engaged in mortal combat, must really and in good faith have endeavored to decline any further struggle before the homicide was committed”; the court concluded that this instruction was unconstitutional:

The right to defend life is one of the inalienable rights guaranteed by the constitution of the state. It is plain that if a person without fault is assailed by another and a mortal combat is precipitated, to require the former to attempt to withdraw before killing his adversary is to require the very thing that may prevent him from defending himself at all. The instruction is quite capable of the interpretation that although the defendant was without fault and the deceased was the aggressor, yet, if they were engaged in a mortal combat, it was the duty of the defendant to endeavor to withdraw before killing his adversary, although he had reason to believe, and did believe, his life was in imminent danger, and that to attempt to decline further struggle would increase his peril and probably enable his adversary to kill him. Such, of course, was not the intention of the learned trial judge in giving the instruction nor, probably, of the legislature in enacting the law, but it is capable of such interpretation and may have been so interpreted by the jury.

had a right to enter, in a lawful manner, the house ... of any person ... for the purpose of talking with and procuring his said wife to leave the said house, and had a right to use such reasonable force and persuasion as was necessary to induce her to ... come back to her home with him; and no person ... had a right to interfere with him in the exercise of such reasonable force or persuasion.

Civil Liability: One case, Kentucky Fried Chicken of California v. Superior Court, relied on a state constitutional right to defend property to hold that a shopkeeper’s agents have “no duty to comply with a robber’s unlawful demand for the surrender of property,” even when the robber is threatening a patron’s life. [There are also other opinions on this question, but they focus on nonconstitutional self-defense or defense-of-property principles rather than a constitutional guarantee.]

Employment Law: Several cases have relied on state constitutional self-defense rights in concluding that an employer may not fire employees for acting violently when the violence was committed in reasonable self-defense. In the course of deciding whether firing an employee for his actions constitutes tortuous “discharge against public policy,” courts often look to whether the state or federal constitutions protect that conduct against governmental retaliation. Such constitutional protection is not necessary or sufficient for the tort to be recognized, but it is relevant to the decision.