The burden of proof is all on them. If they file suit, you will want to pay close attention to the deadlines. The clerk of court can offer some help. It will not be easy for them to prevail. The judge will not look favorably on the facts of this case. If you want additional help, try your local legal aid office.
The $200 comes from a civil statute. It is very doubtful that the store will actually file suit over this amount. The more important case was the criminal matter which seems to have been resolved in a way favorable to you. If you are sued, it will be in small claims, and that is a matter for another day.