More than 10 years ago, I had a similar incident where I ended up kicking down a guy who tried to mug under similar circumstances. While I was readying myself for his next attack, a large heavyset taxi driver came out of nowhere and yelled how he was calling the cops. The dude ran off. It was only then in that split second that I realized the homeless guy's hand had been reaching into his back pocket for a knife. I would have walked right into it. That's the kind of trouble training in martial arts like karate will get you in -- over-confidence a few critical degrees removed from reality. That realization nearly made me faint.
After that, I started carrying whatever was legal or near-legal - and getting appropriate training. For example, Mace was the most portable least offensive tool. Sometimes, I pushed it with a telescopic baton. And, in the UK - with all sorts of draconian laws virtually eliminating any reasonable self-defence
http://www.donrearic.com/defendingyo...inbritain.html innocuous items one could explain away as 'everyday items' like a Surefire E2D or the Cold Steel "Pocket Shark":
http://www.coldsteel.com/pocketshark.html
Since then, I've had only about three incidents in the US and UK where being "paranoid" (as some of my colleagues have claimed likening me to Bernard Goetz) made the difference in me becoming a victim. Many more times, where I guessed there might be trouble, I didn't hang around to find out - none of that shit will help if someone decides to pull a gun on you. However, I've never had to complain about being a victim.