Would you be concerned?

As mentioned in the previous post, I changed the oil this weekend on my sons Honda Civic which we purchased new in 2010.
After changing the oil, I noticed on the oil cap, there was a little creamy colored oil. Typically this means water in the oil. The oil was pure black and showed no signs of water. My thoughts are that he is living and working up north of me and until he finds an apartment, he is living at my sisters house, and drives a whole 4 minutes twice a day to the train station. I'm guessing the PCV valve isn't blowing out the condensation as the car isn't getting hot enough for the valve to work.
I asked him to keep an eye on his coolant level as possibly a head gasket could be blown or leaking.
Any thoughts on this?

I've had a few engines that had milky oil on the fill cap with no coolant issues.

Condensation likely as you mentioned. Nothing in the oil, you should be good.

I agree. I experienced the same thing years ago when I only drove short distances.

I noticed that the oil cap seems to have a piece that broke off. While it still fits in the cap like an "O" ring, it is not connected. I'll order a new oil cap for a piece of mind.