Yep, I can attest to this. Seems to happen when you attempt to use the kitchen unit to fill up an object that’s already full; for some reason, this empties the water tank to a very small negative number, causing some sort of underflow glitch that henceforth gives you infinite water to drink.
Similarly, one can fill the kitchen unit with a very small amount of water, the remove it by filling that water into a container, and you’ll still be allowed one drink from the kitchen unit despite its tank being empty.