Admin Menu doesn't use permissions to display top level admin navigation items

I'm not sure if this is a documentation issue or a functionality issue...

The Readme document for Admin Menu states:

Note that the menu items displayed in the administration Menu depend on the
actual permissions of the viewing user. For example, the "User management"
menu item is not displayed to a user who is not a member of a role with the
"administer permissions" and "administer users" permissions.

I have two different D6 sites that do actually display the "User management" menu item (as well as all other top level admin categories, such as "Site administration," "Site building," etc.) regardless of whether the user has a role with permission to do anything within those categories.

For example, one user I've tested has only the ability to create and edit certain types of content, but still has the User management menu item displaying (no menu dropdown). If the user clicks it, a page appears that is blank except for the page title. This is the same for the other categories (except for the "Content management" option, which displays and works as expected). I've confirmed the user does not have a role which allows "administer permissions" or "administer users."