Since I started the "jab thread", I thought I would add where I am coming from. I am a Corrections Deputy, with over 3 yrs. experience. I've seen alot of fights and have been in alot of fights. Let me tell you, some of them are "trained" people, even though they have never stepped foot in a gym or dojo. They practice shadow boxing, talk to each other about fighting techniques and have lots of street experience. Those are the ones I had in mind when I asked it. I was thinking of a trained criminal, someone who doesn't care if he starts a fight and doesn't care what he does to you.
I agree with most of what you said, it is very rare to be in a fight with someone who is trained. BUT, my safety depends on knowing what to do when I do meet someone who is trained. I've seen alot of "trained" martial artists loose to an "untrained" street fighter because they assumed he wouldn't know how to fight.