But I am simply not going to worry about something which has never happened, ...
Not to be argumentative, but I've heard that sentiment before, more than once, though not in the context of anything related to violence. More than once the results were very unpleasant indeed if not disastrous. The phrase used varied somewhat from time to time, but it came to be known among us as "famous last words."
It must be pointed out that no one can know for sure that something "has never happened". Search engines are amazing things, but they will not find for you the notes taken during investigations or during plea bargaining negotiations, or transcripts of jury deliberations. Unless something has gone to an appellate court, the details are going to be very hard to find, and unless someone chooses to write about something that he or she was personally involved with, that something will probably remain in the realm of the unknown.
...as people have found out in instances with which I am familiar.
Of course, there is also the fact that there is a first time for everything.
When the amount of historical data is scant or the data cannot be found, one has to use other means for risk analysis. Simulation and testing can serve well. There are just not very many self defense shootings to analyze, and there are far more variables than there are results, making it impossible to draw definitive conclusions from history.
I'm perfectly willing to learn from mock jury results without asking about what may or may have happened in the past.