If you're not a huge guy and you find yourself in this situation (which could happen pretty easily in NYC right now apparently), what's your tactic? What's your tool?
There's not a solution to every problem; there are such things as no-win scenarios.
In your scenario, you had a number of chances to get out of the situation safely and you chose not to exercise them until it was too late to extricate yourself safely.
I suggest that when things FIRST start to look ugly, you worry slightly less about your constitutional rights and your job and slightly more about keeping your hide intact. After all, if they beat you up or kill you, are your constitutional rights going to make the bruises and broken bones go away? Will having a job restore proper brain function or bring back your life?