Should I fight a NYC Fare Evasion Ticket?

My friend and I entered the 8th Street-NYU subway station. There was no metrocard machine, and my friend was short on his fare. In an effort to avoid missing an approaching train we entered the turnstile together, using a swipe from my unlimited card (which I purchased two days prior to this event). Two officers saw us, and ticketed us both for fare evasion. Technically only one fare, my friend's, was evaded. Do I have a case, or does aiding in evasion carry the same fine? I can't find anything in the rules and regulations section on the MTA website.