But the circumstances of Sir Ian's resignation yesterday - effectively sacked by the Mayor of London Boris Johnson on his first day as chairman of the police authority - raises issues not just about Sir Ian's fitness for the job of Commissioner, but also about Mr Johnson's fitness for the job of Mayor.
As the increasingly impressive Jacqui Smith pointed out in a Question Time performance of cool, controlled anger, there is a clear procedure in place for the removal of a Commissioner involving the police authority - not just its chairman - making a recommendation to that effect to the Home Secretary.
By failing to follow this procedure, and behaving instead like a tinpot dictator, Mr Johnson has not only managed the considerable feat of inducing sympathy for Sir Ian Blair, he has demonstrated once again his deep and ineradicable buffoonery.