This has been my general rule as well. Just stand back and wait, if help looks like it's needed, do so. Usually that same person will help you out in return. I helped a group on kaas once that was having trouble with a boss, I had my upper lvl sniper, we killed her quick. They offered to compensate me, and I told them don't worry about it. Hopefully they will carry that forward, but it was just good gaming, imo.