While they probably might win in court, the question is will it be worth the time and expense. Because the probability of them being cited and having to go to court is better than 50%. It would be a he said they said type conflict and most police I've delt with tend to refer that to the prosecutor to deal with. So then you need to get a lawyer and spend time going to court.

I'd still call animal control and submit a report, so they have a record in case this has occurred before and they have a nuisance dog file open.