Based on the posts Thank you, Shog9 and Thank You, Robert Cartaino, they no longer work for Stack Exchange, and their moderator access was revoked from all the Stack Exchange sites.
However, when I see the Area 51 Discussion Zone Moderators page, their accounts are still listed as moderators.
But when I checked their Area 51 main accounts (Shog9, Robert Cartaino), the moderator access is removed as well as in their Network Profiles (Shog9, Robert Cartaino).
So it seems to be a bug to me, or is this a special case for Area 51 discussion only?
If not, can the information about the user's moderation be updated in Area 51 Discussion Zone too?