The statement that the big pub crawl downtown is just Pokemon Go fans can not be proven to be true or false. While Pokemon Go has become a popular mobile game that involves walking and exploring real-world locations, it is not possible to determine whether every participant in a pub crawl downtown is playing the game. Many factors can influence the composition of a pub crawl, such as the location, timing, and promotional efforts, and it would require specific data and observations to make a definitive conclusion about the participation of Pokemon Go fans in a particular event.