For moderators and administrators they are able to see hidden members. Hidden members show up fine on the index page, forum pages, topic pages, etc.
For a moderator or administrator, when viewing a topic, the hidden users status shows up as "online" while for normal users and hidden user shows up as "offline" as expected. However, when a mod or admin views their friends/foes, hidden users show up as "offline", where you would expect them to actually be shown as "online" to be on par with the rest of the board results for online/offline status.