Ok, so twice this week I've seen a cyclist from one team taking a bottle from another team's soigneur. How does that work? Both times, the soigneur had a rider from his team in the same group as the cyclist who ended up taking the bottle, but it was like, no big deal. The cyclist didn't even hand the bottle over to the rider from the other team. I guess this is not problem?
I saw this during E3-Harelbeke (I think it was Sky taking a bottle from OPQS, or maybe the other way around) and then again during Gent where OPQS took a bottle from a BMC soigneur.
As long as it doesn't take away from their own riders, or cost them (time, money, energy), or give an advantage to the other team, soigneurs always help eachother out. And even team managers have been known to help out opposing riders (drafts with cars, bottle handups, etc...). When they're nearing the finish of a race and in the "heat of the moment", though, watch out.