He was asked to track down the delegate "Aspex Ibarra", whom his boss suspects of being an Evil adventurer in for a rude awakening when Valia Wain finds a test of Evil that actually works. He suspects he knows who that is from the very beginning. It doesn't take much of a description of the man to confirm it.
Rather than try to scry Alexandre Esquerra, which is expensive and probably won't work, he just goes to his house and knocks on the door. He's wearing his own face, which commands enough respect (and fear) among the ex-Chelish adventurers of the world that it's worth the brief risk to his own security.