I read a couple of answers here, but I thought I'd give my 2 cents anyway. I mostly agree with the others that said it's not a big deal and seems to be a principle of hers.
I saw that you're not from the US. In Germany, there's an unwritten rule that you never bring any kind of food or beverage to a restaurant. We have other fun stuff like most restaurants not giving out free water or charging you for using the toilet if you haven't bought anything.
I could see her being upset with you if you drank your own water and ate your own food in the restaurant. But, again, that's only from my German point of view.
Okay, I don't agree with what you said at all. But for argument's sake, how do you justify that they arbitrarily can raise a fine to a substantial prison sentence? That doesn't even make sense, not even by your logic. You just said what you think is just, two months of his wage.
So what did he do between insulting somebody and appealing in court that was so bad? Appealing in the first place?