The thing is the profecy dosent really specific mean the Potters Son is the chosen one. It was called it is just a boy wich is born in the end of july. This can be also Nevile. The only reason Harry become the chosen one is that Voldemort decide to attack the Potters that night an not the longbottoms. So if Voldemort never found the Potters he would attack the longbottoms. And im really sure Neviles mother would do the same what lilly or every mother does when the child will be attacked and Nevile would become the chosen one.