Originally Posted by mjbuckely
Maybe they just didn't look underneath.
It very well may not be a plumbing issue at all. Something like that is 'really' difficult to track down unless you can find something somewhat suspect to follow up on.
I certainly wouldn't ignore it, but it might just be condensation. It's very difficult keeping an underbelly completely water free. If there is concern it certainly wouldn't hurt anything to drill a couple of small weep holes through the underbelly in the low spot and let it drain.