Special Advisors Make Policy Decisions?

You may recall the furore over the statistics released on knife crime recently. Via Politics Home I see The Guardian is now reporting that a political advisor 'overrode' the NHS's appointed Chief Statistician's wish, said wish was also being backed by Department of Health officials.

Now, in my innocence, I always thought that politicians were elected to 'run' the country and decide policy and that this did not include an abrogation of that responsibility to an unelected and unaccountable political appointee.

Mind you, elect a load of amateurs and what can one expect?