When in multiplayer, your 'Recruited' NPCs show as 'Recruitable' to other players. Interacting with those NPCs has the recruitment button disabled for other players.
Expected behavior:
Free NPCs show as recruitable to everyone
Recruited NPCs show as recruited to everyone
Observed behavior:
All NPCs not under a players control show to him as recruitable, even if they are already recruited by others.
Details:
This happens both on NPCs teleported into realms with players and NPCs existing already in realms. It can be observed by having two players with no recruits going to the Antiquarian site of power and having one recruit the quest NPC there. The NPC will not change status to the player not recruiting him