On all the long haul flights that I have been on, the water comes from a bottle. They just pour up a bunch in the galley rather than taking the carts out.

I would gather that you may have become sick just by being in the close proximty to so many people for long periods of time and the terminal in included. Not to mention the drying out of your mucus membranes that happens on long flight due to the low humidty of the aircraft cabin