I'm not a lawyer but I was a security guard at JCPenny while going through ERAU. I have to agree that it is not in a companies best interest to persue a trespassing charge. Every one we apprehended for shoplifting was ordered not to reenter the store by the police and we maintained photo records. Even so, we never brought up trespassing charges agianst people who trespassed. (We just waited for them to steal again then apprehended them for larceny). Trespassing is such a petty crime that it doesn't make sense to expend company finances on legal fees and payroll for employees to attend court proceedings.

I too wouldn't sweat it, this seems like something that can get cleared up because it was just a misunderstanding. Keep your head high, it'll work out in the end.