The truth is antiseptic, and for many if not most people, the implication of the saying is blatantly true:
“I’m willing to defend my life against an aggressor if necessary with their life".
TXAZ, I think that is a reasonable conclusion. It is certainly not the only one though. Law enforcement, a prosecutor, grand jury, judge or jury might conclude your statement indicates a lack of respect for the law, a premeditated decision to shoot first and ask questions later, or even a desire to use lethal force. The "blatant truth" is any statement other than, I was afraid for my life or the life of someone in my in my charge, to justify using lethal force is unnecessary and unwise. Why make provocative statements?