Blowing the Whistle

So I've always wondered when someone decides to blow the whistle, what put them over as to why they did it. What did that person do to cause this to happen and more so how long had it been going on before they decided to act. What thoughts go through their heads and how do they come to the decision to call someone about it. For example, if you knew one of your coworkers was stealing office supplies for personal use would you call, or if they were stealing them for sell online would you get upset because you didn't think of it first. Would you try to go in on the business venture with them? Or blackmail them in the end, I think the same could be said for healthcare. On Grey's Anatomy, one of the doctors changed the medicine for a patient in a trial and was caught by another doctor. They were friends, but because they were both competing for the same position; he told the chief of staff about the incident hoping to get them pushed from the job opportunity. What ensued was the staff was upset that he told and he was not given the job in the end because of it. Was what he did ethical? Yes and no. Yes because by the other doctors actions she had pretty much caused the trial to not be considered valid anymore. And no because he told for the wrong reasons, not because of the trial but because he wanted the position and felt that telling would help him get the position. So what should he have done. In that case it's hard to say. But it always makes you wonder, when should someone blow the whistle?