2004 Toyota Corolla Water dripping from front of undercarri

I noticed some water dripping from 2 openings in the undercarriage of my car (not a lot, just a small amount that formed a little puddle about 4 inches across) not far from to my passenger side tire. My boss (an engineer) looked under my hood and told me that it's probably either one of the drains (I have a sunroof and I also washed the car over the weekend) from the sunroof or under the hood as there is no water collecting where it shouldn't be (he looked under the hood and under the car as well), or that I drove through a puddle (which I don't remember doing and it hasn't rained for a few days). It was definitely water - not any type of fluid or oil - it was clear and odorless. The final possibility, he said, was a hole in my exhaust system - but he doubts it since I'm not having any problems with the car nor am I hearing any unusual sounds when I drive. Can you tell me if the most likely cause is either that it's a drain or a puddle or if there's some other problem it could be?