What Perry said next was:
"Don't pretend not to understand, Ian"Well said.
There is a style of argument that is so common amongst those who were educated at public schools that I suspect the Headmasters' Conference insists it is included in the curriculum.
When you say something they do not agree with, particularly something a bit left wing, they do not disagree with you: they act as though your argument is so baffling that they cannot make anything of it. Hislop does it all the time, though his conservatism is more cultural than political.
In future I shall use Grayson Perry's retort when faced with this tactic.