The whole interaction lasted less than 10 seconds and ended with the guy going somewhere I couldn't follow him. Finding him, beating him, taking his picture, hell, even engaging him in an argument were all impossible even if I wanted to.
Whether I cut him off or not is a matter of conjecture. I ride my bicycle in the City too, so I like to think I'm courteous to our non-motor 2-wheel brethren. Clearly this guy felt differently. I think that giving 50 yards of space after I passed him before I turned was enough but given his tone, his threats and the fact he rode off without even giving me a chance to either apologize or argue leads me to believe he's a pretty high-strung individual. With all that in mind, I'm still interested in what people think is the best course of action moving forwards. For the time being, I've moved the bike.