Yep. Deontologies have useful... consequences.

This is why you should make sure Dave holds a deontological ethical theory and not a consequentialist one.

No it isn't. I just have to make sure Dave has an appropriate utility function supplied to his consequentialist theory. Come to think of it... most probable sets of deontological values would make him release the uFAI anyway...

If Dave holds a consequentialist ethical theory that only values his own life, then yes we are screwed.

If Dave's consequentialism is about maximizing something external to himself (like the probable state of the universe in the future, regardless of whether he is in it), then his decision has little or no weight if he is a simulation, but massive weight if he is the real Dave. So the expected value of his decision is dominated by the possibility of him being real.