I would like to talk about the commissioner's role or mandate. If we're talking about ethics based on values, then an advisor would be an appropriate choice. However, if we're talking about a code of ethics, and violations of certain standards, then the choice should be a commissioner with vast experience in investigations, because allegations of breaches of a code must be founded in fact. Finding the evidence requires extensive interview and analytical experience. A background in ethics would be an asset for someone acting as an advisor in cases of non-compliance with certain values, for example, an individual innocently doing something that was not allowed. On the other hand, in cases of deliberate attempts to break the law, an investigative approach is necessary, one that involves collecting facts and evidence that will ultimately lead to recommendations. The ideal candidate should have both types of experience.
On May 31st, 2006. See this statement in context.