Also, he says that St. Robert Bellarmine never envisioned a situation where there's no one left in the hierarchy to call out a heretical Pope, but they would deal with it ... whereas now the entire hierarchy are corrupted and are never going to remove him, so this situation is beyond human remedy and can only be solved by God.
Well, that is pretty close to what St Robert Bellarmine did actually say, not specifically with reference to heresy and a corrupt hierarchy, but in terms of a pope wanting to destroy the Church with no human remedy. I don't think we can say that he did not envisage this possibility:
On The Church, Vol I, Bk II, On The Authority of Councils, Ch XIX, Protestant Responses are Refuted:
In the second place he proposes arguments of John Gerson:...
2. The Pope is a member of the Church, therefore he is lesser than the whole, which is the Church, and may and must be cut off if he would corrupt the Church because it is from natural law that members corrupting the whole body must be cut off...
To the second consequent it can be said:
firstly... secondly...
But they will say, therefore, only the Church is without remedy if it has a bad Pope, and the Pope can disturb all things unpunished, and destroy and no one will be able to resist.
I respond: No wonder, if the Church remains without an efficacious human remedy, seeing that its safety does not rest principally upon human industry, but divine protection, since God is its king. Therefore,
even if the Church could not depose a Pope, still, it may and must beg the Lord
that He would apply the remedy, and it is certain that God has care of its safety,
that He would either convert the Pope or abolish him from the midst before he destroys the Church. Nevertheless, it does not follow from here that it is not lawful
to resist a Pope destroying the Church: for it is lawful to admonish him while preserving all reverence, and to modestly correct him, even to oppose him with force and arms
if he means to destroy the Church. For to resist and repel by force of arms, no authority is required. See more on this with Juan Torquemada, lib. 2 cap 106