Anglicans have commonly complained about the definition of Papal jurisdiction in Vatican I as an Ordinary, Episcopal, and Immediate jurisdiction over every Christian. It apparently subverts a doctrine of Episcopacy (sometimes called 'Cyprianic') which has often attracted Anglicans. "It makes the Pope a parallel and superior diocesan bishop in every diocese of Christendom", is the criticism.
Dom Gregory Dix dealt with this by referring to an incident in Anglican history in which, a diocesan having refused to institute a parish priest, the institution was therefore performed, after the legal processes ended with the diocesan losing the case, by or by commission from the Archbishop of Canterbury as Primate. As Dix pointed out, this is Ordinary (in accordance with norms of canon law) Episcopal (conferring the Cura animarum) and Immediate. If Anglicans can accept this, they need have no problems with Pastor Aeternus.
I assumed that this referred to the Gorham judgement of the 1840s, when a High Church bishop, Philpott of Exeter, refused to institute an Evangelical incumbent who denied Baptismal Regeneration. But Fr Alan Cooke of S Mark's Chadderton wrote to me in 2009: " In the early days of Archbishop Lang's primacy, as related on page 379 of Lockhart's biography, Bishop Barnes [the ultra-Modernist bishop] of Birmingham refused to institute a priest of whose views he disapproved. After proceedings in the High Court of Chancery, the Bishop remained intransigent, and the priest was instituted by the Archbishop. I wonder if it might be this incident that was in Dix's mind. He would certainly have had more sympathy with the view of that priest in Birmingham (the Revd Doyle Simmonds) than with those of Mr Gorham."
This may very well be right. But - if I may play Devil's Advocate:
(1) the Gorham case was much more high-profile; and contributed to Archdeacon Manning's departure from the C of E; and
(2) if Dix had 'Gorham' in mind, he really is taking the war into the enemies' territory by arguing that even the most anti-papal factions within Anglicanism are delighted to have a Pio Nono on tap when it suits them and their proddy cause. This is the sort of cheeky ad hominem argument that Dix, like Newman, loved to employ.
I use ad hominem in the Lockean sense of pressing a man with the implications of his own assertions.