Right from the admin guide:
Higher level admins
If they are on then it doesn't mean you leave everything on them. If u see something wrong handle it by yourself. Because sometimes i am on and i am AFK and same goes for all. If u see anything wrong try to fix it. If u are fixing in wrong way u will get PM by higher level admin so u know how to do it next time.
We all work together as a team. If I warn a guy before a Co-Leader, it's just the same as if you warn the guy before a Co-Leader.. or even a Leader. It means you helped, and he was able to continue his game, or work on forums, or speccing someone without having to stop and deal with that problem also