Theoretically Remy could get away with crimes scot-free if he so desired, if Linguini were to be put on trial and he accused a rat for his wrong doings, no one would believe him. It is quite responsible of Remy to not use his powers in such a way, but instead to help out this human and create a bridge of peace to the very species that has wronged his kind for centuries. Remy is the textbook definition of a hero using his powers for goodness and humility rather than getting even, refusing the ever-so tempting path that is evil.