Callistemon
^Sir Simon's description is perfectly accurate; the NHS is exactly that; the calm centre of a raging storm.^
That is a good interpretation of what he said.
That's how I would read it too.
In any case, the fact that someone went to Balliol means that they had good A level results or went to one of the most prestigious schools - not that they necessarily know everything about everything. I understand that Sir Simon Stevens studied PPE, not etymology or idiomatic language, so his degree and place of study is hardly relevant, is it?
Could this be a thinly disguised dig at the Labour Party by any chance?