Should a single incident of incompetence or negligence be enough to warrant discipline?

The Legal Profession blog is reporting on an interesting case in which the West Virginia Supreme Court of Appeals imposed sanctions on an attorney for what some members of the court thought was merely a single act of negligence. The case is called Lawyer Disciplinary Board v. Burke and it is available here.

The case is interesting because it raises the question of whether minor transgressions should subject lawyers to discipline.  Or, in other words, the question of at what point does a particular misconduct is "bad enough" to warrant discipline.  The majority opinion rejected the lawyer's argument that, even tough negligent, his conduct did not rise to an ethics violation, while, in a dissenting opinion, Chief Justice Ketchum argued that "nothing [the] lawyer...did came close to being an ethical violation" and that a single act of negligence should not be considered to violate ethical standards. 

In fact, the Chief Justice opinion could be interpreted to say that there should not be discipline for any act of negligence:

The problem with the majority’s opinion is that it fails to define disciplinable incompetence with any clarity so as to allow for predictability. Single lawyer slipups are generally not ethical violations. They may expose the lawyer to professional negligence liability, but it has nothing to do with the lawyer’s ethics. Discipline should only be imposed when the lawyer’s error is intentional, reckless, repeated, or accompanied by some other misconduct like concealment.

What the Chief Justice is saying that a single incident of incompetence would justify discipline only if it was intentional.  But, if it was intentional, then it wouldn't be negligent, would it?  And, he also says if it was "repeated," in which case it would not be a single incident...

I don't necessarily disagree that a single instance of negligent conduct, depending on the circumstances, does not need to result in discipline, but this general assertion by the Chief Justice seems to be too broad.  Discipline can not be limited to instances of intentional conduct.  The very notion of incompetence is based on the fact that an attorney may violate a rule of conduct without intent.  Limiting the disciplinary system to the regulation of intentional conduct is not supported by the current regulatory approach and would be wrong and dangerous.