"If some wacko tackles you or gets up in your business, this could be a good last resort."
Just because someone tackles you and tries to steal your wallet doesn't mean you can stab him in the neck three times and watch him bleed out. I guarantee some prosecutor will make sure you get 20 to life... Good situational awareness well get you out of, or keep you out of 99% of bad situations. With that said. I would give some serious consideration to using your new blade as a neck knife, much better concealment and almost a zero chance of the BG getting to it before you do in a scuffle.