From what you wrote, it seems you did perfect. I teach CCW in my home state and have reviewed thousands of similar scenarios. Bottom line, you can only pull a firearm when you feel threatened with immediate death or great bodily harm.
You had the right to feel so threatened when he moved his hand out of your sight and it was clear by his words and actions, especially after a verbal warning from you, his intentions were clear.
The only thing some liberal jerk prosecutor could hang his hat on was that the poor 'victim' was only after your car and not you. Different states have different laws on protection of property.