In 2001 Canon Norman wrote An Anglican Catechism, which the Church Times praised as "coupling innovative sexual views with traditionalist church teaching, and which Richard McBrien described as "A very Protestant view of the Christian faith" in his review for The Tablet. This year he published Anglican Difficulties: A New Syllabus of Errors, which the telegraph described as "one of the most ferocious assaults ever launched on the Church of England," marking, in the space of 4 years, a radical development in his thought.
Apparently Canon Norman has been wrestling with the question of authority and an infallible teaching office for some time now. The Anglican blog Pontifications picks up the rest of the story, posting some choice excerpts from his 1998 lecture "Authority in the Anglican Communion". Well worth reading.