[Dragokas]

8guawong, thanks. You are right. I made a problem myself by Unhooking on "disconnect" reason.
I thought player_team set that reason when player is really disconnect from the server.

Looks like my main question is over. After hooking it once, engine never unhook it again itself.

So, how to recognize is it disconnection because client quit the game or because map ends?
OnClientDisconnect() forward is also called for all clients just right before map ends.

EDIT.
Ohh, MasterMind, Crasher, thanks too.