[EDIT: Keep in mind that the developer quit; the startup had to hire someone else to take over in order to get its product launched. What was the company supposed to do, fold its tent because one unpaid consultant -- who had also been given company stock, BTW -- decided to throw his legal weight around? I doubt many founders would agree.]
I sympathize with the developer, but in this case he shot himself in the foot just as surely as the company did.