I can't locate the piece I was thinking of but this may help as it is from UL. It clearly points out that incidental water contact is not an issue. Look here:
http://www.ul.com/global/eng/pages/.../electrical/additionalresources/flooding/nmb/
Is this the same piece you found?
I might add that I know of a fair number of AHJ's that insist on full dry-in before NM cable is installed. Many even have definitions of what is dry-in is. That said, even the UL piece says the NEC does not require this. I think that there is a big difference between installing NM cable that may get a little wet and installing, say, a breaker panel(even without breakers) or a wiring device.