He never actually treated childhood Gender Incongruence, never worked in GIDS and in fact worked on adults in a completely different department in a completely different building.
He has presented a story where a group of transphobes and conversion therapists who had infiltrated the organisation over time met with him in secret and presented their 'concerns'. In truth, these were largely historical issues from disgruntled ideologues about the more chaotic early days of the service alongside a rising tide of reactionary transphobic rhetoric - much of which was espoused by staff who had found their growing hostility toward softening cultural attitudes toward trans people and the neutrality of a 'trans outcome' to be incompatible with a service that centred a compassionate policy of epistemic justice.
A dubious doom-laden report was submitted by him to the Board of Directors,
which the trust identified as comprising a list of historical issues which had already been addressed and inciting even greater abuse toward existing staff. He was threatened with disciplinary action and then quit rather than be fired.
He has since been lionised by the reactionary press alongside two prominent conversion therapists - one of whom used to work in GIDS but left when it became clear her views weren't compatible with actually providing meaningful treatment to the children she'd been charged with helping.
You'll find most of the rhetoric surrounding GIDS is hopelessly naïve, often involving highly confused timelines that shift events and schools of thought around by whole decades at a time, and clearly focussed more toward building a sensational and spicy story that will drive headlines than it is toward accurately reflecting the true events.
Truth is often the first casualty when a hack with an agenda catches a whiff of a career-making big break.