... working for someone, right? So, if maybe you went to work for them as well, you would find out more 
Like the key phrase he is waiting for, that may make him more friendly to you. Or (see this thread: http://www.softwarespecialties.com/cgi-bin/rpgforum/dcboard.cgi?az=show_thread&om=386&forum=DCForumID19&archive=yes)
you can cast a high level mindread on him to pick soem secrets ... or another thread says you can pick pocket a fake badge off him.
Tools for Wizardry(r) 7