While this is, at heart, a semantic debate, the point is most certainly not moot. (Nor is it mute, but that's another story... :wink
Everything you say can and will be looked at by the prosecutor, by the grand jury, and (possibly) by a jury. In all likelihood, none of these folks will be experts on guns, justifiable shootings, etc. Your choice of words (and, to a lesser extent perhaps, guns and ammunition) are going to be looked at by
people not by Law Robots. If you say that you meant to
kill, rather than to
stop the immediate threat, your actions could very well face scrutiny that they otherwise may have avoided. It makes absolutely no sense to choose language that can only hurt you should you ever be faced with a criminal or civil prosecution.
Worst case - you go to prison for a long time as a "killer." Best case, you spend time and money (and money, and money) defending yourself against charges that could have been lessened or made to go away entirely if you weren't so quick to spout out how you "intended to kill" to anyone who would listen.
Also, caliber and weapon choice
have been shown to influence a jury in at least one case. Read Ayoob - he has an incredible library of cases where folks who should or could have escaped criminal conviction DID NOT, and went to jail even though their shootings were - all other things aside - justifiable. Cocking the hammer on a double action revolver, for example, contributed to one man going to prison...you just never know, so for cryin' out loud eliminate all the questionable things (like saying you meant to kill) from your routine.
Lastly, you generally have no legal responsibility to aid ANYONE, much less someone who just tried to kill you. Unless you are a doctor/paramedic/EMT (and then, only maybe) will you be required to render aid, and even then only if it is safe to do so, and only within the limits of your training and abilities.
And Gator, to answer your question - if you want the Kel Tec, get it. Load it with high quality expanding ammunition (similar to that used by almost every law enforcement agency in the country) that feeds reliably and that you can shoot well. Then, practice, and don't worry about your choice of weapon/ammo.