The policy with kicking other admins that are in spec is to ask them in admin only chat if they are there and if they do not respond in a reasonable amount of time to kick them. This originated from some admins and even clan members that constantly sat in spec to help increase server ranking stats and or to get more people to join. It is a commonly accepted rule that admins can kick each other when afk for an extended period, this is also because the admin has a reserved slot anyways so it is not as though they can not get back into the server.

As for that guy who was banned, you were already unbanned so it must have been a temp ban or something.
Also sorry for no responce as my computer crashed last night when I tired to load CS:S...

In the future I would only ask that 1) if you are going to be afk and do not want to be kicked tell the other admin 2) If you are going to kick an admin be sure to send them a few messages in admin chat first because they could be in spec demoing or something else that is important.