What did I do wrong here?

On the way home tonight. I was at a light. The left turn arrow turned green. I turned but not quickly enough for the guy in the pickup behind me.

He honked. I don't take kindly to being honked at, especially when I didn't do anything illegal or dangerous.
I stepped on my brakes again and he honked again. Because the road I was driving on had several potholes, I drove kind of slowly, again, more slowly than he would have liked but nothing illegal. He flashed his lights at me.
I rolled down my window and gave him the finger, I'll admit I probably should not have done that, but I don't take kindly to being honked at or having people flash their lights at me.
If a cop wouldn't have stopped me for it, you have no business honking at me.
We got to a light and he pulled up beside me and rolled down his window. I rolled down mine. We both started yelling. he said I needed to take the turn more quickly and I was driving at 20 mph, which he thought was rude. He was also really mad that I gave him the finger.
I just yelled at him that I did nothing wrong and he needs to grow up.
After the light, he followed me for a bit then passed me.
I didn't know taking left turn slowly was illegal or dangerous. I don't think it's particularly rude, either.
Maybe he was sick and needed to get to the hospital, but there are these things called 911 and ambulances and if he was sick that's what he needed to do.
Maybe he was late for work and in danger of getting fired, but that's not my problem.
What did I do wrong here and could I be getting a visit from the police?

 

You did the equivalent of posting on SJ.com. If you post frequently, someone is just bound to have an assholish reaction to a post. Same with driving.

 

Yes but why do people want to kill you when you do something rude when driving even if it's not rude.?

 

If you woulda had a gun, you could have shot him. Then you coulda been famous.

 

It's only driving. I wouldn't shoot anyone.

 

You cannot be this naïve. So you're concern trolling ... yourself?

 

No, I'd like to know what I did wrong. Really. Why did he honk at me?

 

Maybe he thought you were cute.
You could be having hot monkey sex right now, but you blew it.

 

I never thought of it that way.

In this case, however, I'm pretty sure he had a problem with my driving that he should not have had.

 

sp, probably the best explanation:

 

With any luck he did lose his job or die on the way to the hospital.
Would have served him right.

 

Green left-turn arrows can be notoriously short. I've seen a couple that are no more than 5 seconds. Having to sit through an extra red light because the car in front of you was dawdling can be frustrating.