Proper protocol?

   I was at a function recently and I bumped into a business colleague that I had not seen in quite a while. Normally I would give him a nice greeting, I would ask how he was and I may either shake his hand or go in for a man hug. But this time it was little awkward as we were both standing in the bathroom at adjacent urinals. So what does a guy do? Do I engage in conversation? Certainly I don't put out my hand or try to hug him. Do I even say hello?
   I guess the same question would arise in any public bathroom. Is one rude if he doesn't engage in conversation in a bathroom? I think a public bathroom is like going to war, get in finish your mission, get out as quickly as possibly with as little collateral damage as possible. Quite different from your private bathroom at home which is like a vacation. An oasis, alone, quiet, and no one bothering you. But what is the proper protocol in a public bathroom?