The Congress' research in the field of space and time was lacking and had not yet formed a complete theory. Thus, it was impossible for the arcanists of the Congress of Magic to determine where Lucien would be teleported to after the disruption caused by Ramiro would. On top of that, Lucien himself is the Secretive. Due to its special abilities as well as this world's disturbance to long-distance magic and prophecy, Fernando and Hathaway had yet to find him.
Lucien concluded that this surveillance specter had fused with his body and soul before he had entered the Portal to Alternate Realm.
Otherwise, how was the man behind the scenes able to find him before Fernando and the Prophet, and let the wraith posses him before he recovered?