In Reimers v Health Care Complaints Commission  NSWCA 317, the NSW Court of Appeal confirmed that conduct flowing from an impairment may constitute professional misconduct.
Justice Basten at  noted that while the proposition that impairment cannot be professional misconduct is true, that is only in the sense that an impairment is not conduct. An impairment may manifest itself in conduct or, to reverse the relationship, an impairment may explain particular conduct in part or in whole.
Quoting from the judgment at  – :
….The applicant says that if impairment were established, as the Tribunal found, he cannot be guilty of professional misconduct: written submissions, paragraph 9. That proposition, however, elides two ideas which need to be separated. The applicant must say either that conduct which results from an impairment cannot be professional misconduct, or that it is manifestly unreasonable to treat misconduct which is the result of an impairment as professional misconduct warranting deregistration.
So understood, the first proposition is untenable. Gross, repeated, incompetent medical practice does not cease to be such because it is caused by an addiction to alcohol, heroin or other drugs. This was not a case where the practitioner was held to be unaware of his condition or its consequences. That he continued to practice as an anaesthetist whilst unable to exercise the necessary care, skill and judgment, could reasonably be found to constitute professional misconduct. The conclusion of the Tribunal that there was professional misconduct was, at least, unsurprising.
The second proposition is also untenable. There is no doubt that addiction is a condition which may, perhaps should, evoke sympathy. The degree to which a criminal offence is caused by a mental illness, including addiction, may properly be reflected in the sentence imposed. Nevertheless, “protection of the community” is a relevant sentencing principle and may, within limits of proportionality identified by reference to the seriousness of the offence, extend rather than restrict the sentence…..