The above clip is famous for the avoidance of a question but it is also an example of the accountability issues with agencitisation of what used to be direct public functions. Where does the buck stop, the senior management of the agency/body or with the minister? This has come into focus in Northern Ireland with the water crisis (and by the way undermines claims that these issues are unique to here).
Since this practice became common the various debacles that have occured have not cleared up the vagueness. In some cases no one has gone, others the senior management and on occasion a minister has fallen on their sword.
PS As I am on the topic it is an excuse to highlight Powell's famous Hola Camp speech about ministerial accountability.