"Moderator Control Panel" he will see in all situations, except when Smod search for a member
and panel with user settings open, than it will show "Admins control panel"
Any way he must check in usergroup if smods are given privileges to admin panel.
If he gets error as you say Mark, probably he knows the url, and cannot login any how.
But how many times he would do that, he knows that he does not have action there.
EDIT: My answer came up without reading @edeless answer#5, I was answering that time