The inquisition was also already suspecting that Voss is a hshar'lak (traitor) before the player even meets him at the camp, since there is a letter on the left side of the room where the Inquisitor can be found, so the clues pretty much imply he ran into the inquisition just like the party has on their way to Baldur's Gate;
[The slate is densely packed with carvings. A few words recur throughout: 'Voss', 'hshar'lak', 'Vlaakith', 'loyalty'. A note has been written over the text in Common.]
Voss - traitor?