Investigative Journalism or a Witchhunt?

In Frontline's story about the expose series the Spokesman-Review ran on Mayor Jim West, Editor Steven Smith said, "If he's [Mayor Jim West] engaged in this activity … we need to know that. If he's not -- there's no story." I took this to mean that the difference between a legitimate and illegitimate news story about scandal involving political official depends on whether or not that official is engaged in illegal activities. If they are, then it is a matter of public concern, but if they are simply engaged in a legal alternative lifestyle, then publicizing it would be more of tabloid-like than real journalism.
Reporter Bill Morlin justified the use of a concealed identity on Gay.com as part of The Spokesman-Review's and the FBI's "sting operation" because he did not participate in it personally. Doing so would have involved him in the story- which would be a violation of his publication's ethics. However, using information obtained by an independent private investigator was not in violation of his ethics- personal or professional. However, I question how he defines his ethics. I suspect that when that policy was written, it had more to do with honesty than technicalities. If you hire an assassin because murder is illegal, you'll still go to jail for murder if you get caught. It doesn't matter who pulls the trigger.
I think that when the story first surfaced to the The Spokesman-Review (pre-published) the paper felt an obligation to investigate. Although bias is not supposed to be a participant, I think that the Mayor's lifestyle choices and age interest contributed to his guilty image. Even though the Mayor maintained his innocence, I think that the adrenaline the journalists experienced for exposing a scandal in the government created a snowball effect that ultimately evolved into a witch-hunt instead of an unbiased quest for truth. I hate to mention it, but newspaper sales were also a likely factor.
The Spokesman-Review benefited at first because it exposed a corrupt politician, but the witch-hunt that ensued damaged its credibility. The scandal hurt the gay and lesbian community because it reinforced a profile stereotype of homosexuality linked to pedophilia. Yet, it may have helped advance gay rights in politics at the same time.
Mayor West lost his career, his reputation was ruined, and one could argue that the stress hurt his battle with cancer. Even though some argue that at least West did not have to hide his sexuality anymore, it was no one's right but his to decide whether or not to stay in the closet. West's guilt would have been the only factor to warrant his outing, and he was not proven guilty. If the difference between a legitimate and illegitimate story is the legality of activity in question, then why did this series appear in the Spokesman-Review as it did?
I think there are ethical problems in the organization of this series. Although journalists are expected to assert an element of scrutiny over the actions of public officials, making connections where there are none proven leads the public- rather than informing it.