Is Jenkins a traitor in Red Faction Guerrilla

Yes, he ends up being one. After finishing the game's storyline, run around and do random stuff for awhile. Eventually you will get a call saying that there is an EDF courier transferring data for the EDF, but instead of a randomized voice telling you to track down the courier, it will be Sam's. Once you begin to chase the courier, you will notice it is Jenkins and you will have to kill him.