I don't know how much of a big deal it would be outside the Tour for someone to urinate in public?
This is a common thing in bike races in general. Often the racers don't stop to urinate. They just go while riding. A domestique might have time to stop? Certainly not a lead rider or even a super domestique.
I'm sure women do the same.
"There's no such thing as shaping and toning. Only stronger and weaker." -Mark Rippetoe