Cycle Rage

I'm usually relatively chilled out riding, I normally shout or gesture but nothing too agro.
BUT, on Saturday I was riding home, a little tired and hung over when I came to some lights on Bethnal Green Road.

I did what I normally do and filter through to the front, down the middle of the two lanes. As I got to the front, the lights went green and I pedaled to get infront of a car coming up on the inside. (Most time people let me across to the curb) but this prick accelerated up behind me as I moved over to the left, he then over took me very closely beeping his horn and shouting through his window. I then shouted something and stuck my middle finger up.

Now I was pretty pissed off at this point because I don't think I was at all in the wrong, so, I saw him stopped at the next lights, I rode up quite fast and ripped his wing mirror off. I then cycled off towards my house thinking there might be a possibility he might catch me up / follow me. Which he did.

At the lights on the junction of Grove Rd and Roman Rd, I looked behind to see him waving his fist at me, beckoning me over and beeping his horn, at this stage I was pissing myself laughing, I then waved at him, crossed the road and nearly got hit as I was laughing so much and rode into the park.

Now I don't think this was an over reaction, the guy was a prick, but I can see why he was pissed off.

The biggest problem here mate, it's likely that he'll be more aggressive toward other cyclists after this incident.

that why I try and avoid doing something like that.