[DannyTN]

"Uh, you're changing the subject. ... you must also consider the likelihood that one's act of stealing will actually prevent it -- in this case, nearly zero"

No, I'm not. The pharmacist doesn't need to consider whether his act will prevent the murder. He just has to know that he doesn't want to facilitate it in any way.

In that respect, it's just like the Hitler guard. His choice is to facilitate the murder or not to. Whether it will prevent it has no bearing on the decision.

[Sloth]

Here's what you asked first:

If by stealing, you could prevent a murder. Would you?

When challenged, here's what you say now:

The pharmacist doesn't need to consider whether his act will prevent the murder... Whether it will prevent it has no bearing on the decision.

If preventing murder has no bearing on the decision, why did you ask a question conditioned directly on that issue? Remove the murder prevention and your first question becomes simply "would you steal?"