You said it yourself; "Admins cannot see everything".
As far as team attacking goes, if I'm on CT and a team attacker is on T, I can't see that he's team attacking, I can only see when he kills somebody. You DO still have an option to be retroactive, though.
http://www.ibisgaming.com/forums/for...p-Ban-Requests
On that forum, you can report people for being douchenozzles after the fact. All you have to do is follow format and provide proof.
http://www.ibisgaming.com/forums/sho...Links-to-Demos
And there's all the proof you need for the last month.
Enjoy!