This provoked a question from Stromness Academy's John Aberdein: "Does that mean teachers must board trains knowing they're heading downhill in runaway mode, towards a ravine where they know the bridge has fallen? The train is called Higher Still, the runaway load is the weight of internal summative assessment, and the ravine that gapes is the loss of credibility of the Higher in Scotland."
Seizing his opportunity, Aberdein went on: "Since the policy of the Educational Institute of Scotland is for the removal of internal assessment at the earliest opportunity, could Mr Boyes please give a view on the likely timetable?"
To which the chief inspector could only reply: "Metaphors are dangerous things. I can't allow a forum on quality assurance to be hijacked by minority interests."