When the ruler of the feast tasted the water now become wine, and didn't know where it came from (but the servants who had drawn the water knew), the ruler of the feast called the bridegroom,

 It was quite certain that an act like the cleansing of the Temple would produce an immediate reaction in those who saw it happening. It was not the kind of thing that anyone could look at with complete indifference. It was much too staggering for that. 