I'm not sure about laws where you are but where I live a hit and run is just that-- leaving the scene of an auto collision without exchanging insurance and contact information with the owner of the vehicle you collided with. Even if nobody is in the car (a parked car), you are supposed to leave a note on the vehicle with your info.
I can understand your being frightened by an big angry guy and not wanting to get out of your car and risk bodily harm, but there was no reason for you to drive off without rolling down your window and trying to talk to the man. If you felt threatened, you could have written your info down and slipped it out a crack in the window to him or driven straight to the police station/called the cops. The cops would have understood if you waited inside your vehicle until they arrived to mediate between yourself and the angry dude. But you really just judged this guy for being upset and tattooed/big (in a high crime part of town) and then ended up breaking the law yourself because you were so worried he was going to do something inappropriate and illegal. Kind of ironic, really.
The whole deal with your lawyer really does convolute your situation though and perhaps you could seek some kind of appeal process citing the bad advice and poor representation you got from your lawyer. As it stands I think the insurance company would be doing something really unfair to treat your hit-and-run differently than any other (believe me that everyone has some perfectly-reasonable-sounding explanation for leaving an accident too, usually that they didn't think it was a big deal or didn't see any damage) but it seems you might have a right to a new trial because the first one was totally botched by your legal counsel.
The bottom line with criminal convictions is that almost nobody feels that they *deserve* the consequence. There is always some reason and back story that justifies why people do the things they do. I think that's why the court tends to look at what people did, the result of their actions, rather than what they were intending to do cuz otherwise we could hardly hold anyone accountable for breaking laws (people always have a lot of outside circumstances that impact why they break laws). I can appreciate your perspective on this (and agree with you that the court might have seen this your way as well) but I also can appreciate how your actions looked to the guy you backed into.
I think that if the other dude took the time to file a police report, it wasn't trivial to him (regardless of the damage or lack thereof to his car, for a lot of people it's just the principal of taking responsibility). And if you drove off without even talking to the guy (assuming he wasn't shaking a fist or brandishing a weapon at you) there is a *really good chance* he thought you were a total d-bag for backing into him and then tearing off.
Also, I hope you won't judge people too harshly for gang related tattoos cuz you never know if those allegiances are relevant anymore. Tattoos are expensive to remove/cover. And even if the guy was a raving skinhead, he still has the legal right to your contact/insurance info if you hit his car. As a woman I know that I would have been intimidated too but I would have tried to remain in my car while talking to him so I could pull off it got out of control.