I've implied the questions and you haven't answered, so let me be direct:
1) Is it in your mind plausible that Fitzgerald didn't know whether Plame was or wasn't covert under the Identities Act within the first week of his investigation?
2) If Plame was not covert under the Identities Act, what was Fitzgerald's legal authority to continue his investigation?
3) Would it be ethical for Fitzgerald to have continued investigating a crime which he knew did not occur?
That being said, I think a malicious prosecution case could be brought with a straight face and within ethical boundaries.
3) Would it be ethical for Fitzgerald to have continued investigating a crime which he knew did not occur?
No. Once he has infomation that "closes the case," it is unethical to continue.
2) If Plame was not covert under the Identities Act, what was Fitzgerald's legal authority to continue his investigation?
The legal authority to investigate operates independently from the facts found. The legal authority is "find the facts, and if the facts indicate breaking the law, indict."
1) Is it in your mind plausible that Fitzgerald didn't know whether Plame was or wasn't covert under the Identities Act within the first week of his investigation?
About as plausible as President Bush adding gravitas to the investigation by similar utterances.
Ethical or not, you must remember that this 'crime' is one the that DEMOCRATS claimed happened, and wanted charges brought against Libby, and him removed from office. (along with Cheney, Bush, Rice, their dogs, and any doghouses on the property)