If I knew exactly who it was I'd gladly report them to the club, but unfortunately I wasn't able to narrow it down to one individual.
Just give them a rough idea where they were sitting, behind the goal would be almost 100% season ticket holders so they will probably be back. Creatures like that can't help themselves and will no doubt come out with more words of the same nature. If the club know roughly they can place an undercover representative nearby for next time.