Ok, well oil is not condensation, but I can certainly see how they'd look similar. I'd much rather see oil on my electronics than water, LOL.
How old is the pad you have? If it's a common occurence, I might look at different solutions. Not sure WHAT those solutions might be, but surely it can't be acceptable to have oil oozing out onto your hardware. Never really worked with an NUC system yet so I haven't encountered this problem and I've NEVER seen this issue with any mSATA M.2 drives I've installed in laptops but I've also never taken them back apart to look for oil leaks. Since it's not a car I didn't figure I needed to. Heh.