Dear neithilath, I don`t think a PM can get away saying that his assistants betrayed him on so many occasions. Being a clean person himself is not enough, he should also be able to control the rogues within his own party as well as be firm with the recalcitrant allies in matters of probity.
Are we able to control everything going under our nose? its so difficult when your so called confidential assistants betray. But MMS should publicly accept(sorry) that his assistants did what he did not expect them to do. This will reduce similar embarrassment in your official life.