The real question is whether you could have won the underlying case which you retained the attorney for. That being said I would suggest you contact attorney Christine McCall. She is an active member of Avvo and deals with licensing issues.
I don't know from 'fiduciary duties,' but clearly there is an ethical obligation to properly and correctly (to the extent that the answer does not simply involve a matter of judgment) determine the potential impact of a conviction. Without more facts, which I am not interested in hearing now, the attorney probably came pretty close. But, as the other attorney mentioned here, if you were going to get convicted whether by plea or by jury/judge after a trial, it really does not make any difference. And, it is not just an issue of 'beyond a reasonable doubt,' you would have to demonstrate actual 'factual innocence,' a very difficult burden (unless you happened to be in NJ at the time of the crime charged.)
Although I am an experienced CA criminal defense and appeals attorney, I can not 'guarantee' that my answer is entirely accurate, since I have not reviewed all of the factual circumstances of the case, nor have I discussed those circumstances fully with the questioner. The fact that I have answered this question does not establish an attorney client relationship between the questioner and my self or my office.
This is not really a "criminal defense" question as it is showing up on Avvo. There may be many reasons why you "should" have taken a plea agreement to your charge. Those reasons may, or may not, still be controlling even if there was correct assessment of the impact on licensing.
If, for example, you were to sue your prior attorney for malpractice, you typically has to prove, as the first answer to this question intimates, that you were actually (not just legally) innocent of the crime and yet, somehow, your attorney managed to get you convicted. (Accepting a plea agreement counts as a conviction.)
On the other hand, your attorney advised you regarding the non-criminal consequences of your plea. My suggestion -- because I'm also a criminal defense attorney and cannot answer this portion of your question -- is that you confer with a civil law attorney to see whether you have a cause of action and what the likelihood of an outcome you desire would be.
This answer is based upon the minimal information contained within your question. There may be other information which could modify or negate the answer I have given. For particularized legal advice, you're always best advised to consult with an attorney personally, so that the relevant "back and forth" can allow for obtaining all information necessary to a complete answer.
You have previously had the benefit of an extended discussion about the soundness of a malpractice claim against your criminal defense attorney for subsequent discipline against your State occupational license: http://www.avvo.com/legal-answers/can-i-amend-a-legal-malpractice-lawsuit--637891.html#answer_1036318
Adding the buzz words "fiduciary duty" does nothing to change the legal analysis applicable in your matter. As previously stated, the remedy for your contentions is to set aside the criminal conviction (plea). That remedy will not bind the State licensing agency, but it may enable a timely legal challenge to any license discipline imposed solely on the basis of a criminal conviction IF you are not barred by statutory time limits and IF you have preserved your objections and rights to challenge. No one here can from this distance make those determinations or any meaningful assessment of the present procedural posture of your matter.
License discipline can occur without conviction and without arrest. Where a State licensing agency proposes discipline against an occupational license on the basis of factual allegations of unprofessional conduct, the licensee has the right to challenge the factual allegations at an administrative hearing before a neutral Administrative Law Judge, and to oppose any proposed disciplinary penalty before the ALJ and the licensing authority board or commission. If the agency imposes discipline (of any degree) against the license, the licensee has the right to a limited, specific, de novo, and expedited judicial review of that administrative action by a Petition for Writ of Mandate (Code of Civil ProcedureSec 1094.5) in the Superior Court.
One of the reasons that you do not have a sound malpractice damages action here -- IMO -- is because (1) you are obligated as a matter of law to exhaust your administrative remedies in the license disciplinary matter and (2) once you exhaust those remedies, your sole and exclusive legal right is to a Writ of Mandate by the Superior Court to correct the licensing agency's error. That is a different right than a right to damages against any person or entity.
If you brought a Writ Petition and were unsuccessful, the Superior Court's determinations in the Writ action will estop you from meeting your standard of proof as to causation in a damages claim against your criminal defense attorney. If you failed to challenge the administrative discipline in Writs and Receivers (Superior Court), then you cannot satisfy your burden of proof in a damages action against the defense attorney because the facts found by the licensing agency can not be challenged or set aside except by timely recourse to CCP 1094.5, and the window of time allowed for a 1094.5 Petition can be very short.
You should at this time invest the effort to consult with a skilled administrative law attorney with deep experience in occupational licensing law to determine whether there remain available to you any legal rights or options.
My responses to questions on Avvo are never intended as legal advice and must not be relied upon as legal advice. I give legal advice only in the course of an attorney-client relationship. Exchange of information through Avvo's Questions forum does not establish an attorney-client relationship with me. That relationship is established only by individual consultation and execution of a written agreement for legal services.