Daniel can be far more cold blooded than the others could ever hope to be, because Daniel is a True Believer. Once he decides what the proper course of action is, he *will* carry through and then he'll sleep well that night because he'll have worked through every permutation and determined that it really is the best course of action. That his moral/ethical center is dead set on the high end of GOOD rather than even over on the edge closer to NEUTRAL, is the only thing that keeps him from being seriously dangerous to the rest of us. He really *should* have shot Adria when he had the chance, but they had him wait and that was out of character. It was a poor directorial choice, I think, rather than a writing problem.

And yes, Vala was already on her downward slide as a believable character in this one.