Lawful Removal of Trespasser

In my state, the law says I have a right to use reasonable force to physically remove a trespasser from my property.
I did just that, first telling the person (who was on my property interfering with a business transaction going on) several times to leave my property. When the person refused to go, I pushed the person a few times until the person was over the property line. I did not strike the person. I did not threaten bodily harm to the person. I merely pushed the person off my property.
Next day, I was arrested for assault and battery.
Knowing that I was within the law, and knowing I had witnesses who gave statements to law enforcement (the day of the instance) that I only pushed the person, how is it that I was arrested the next day?
At trial I was ruled innocent as well as justified in my actions.
But I feel I was wrongly and illegally arrested and that there was no probable cause seeing as how I was on my own property dealing with a trespasser, with witnesses.
I want to file a lawsuit against the county for this *false arrest*... What are my chances of winning such a case?

Chances are very small.

The police have to use their best judgment but the court ultimately decides if they were correct. They were not here and that is normally it.

You have to show some gross violations of procedure to even think of suing.

Thanks..