I used the words I did basically because, in this debate, my sympathies are with Ayer rather than Collingwood.
RGC called Ayer a fool for his logical positivism. (And imo made his case.) — tim wood
I've gone back to my copy of Ayer's memoir, "Part of My Life (1977)", which confirms that, as Oxford colleagues, he and Collingwood were on good terms. Ayer says that RGC "did however take the book [Language, Truth and Logic, 1936] seriously enough to devote part of his lectures to refuting it. He ended one such lecture by saying 'if I thought that Mr Ayer was right, I would give up philosophy.'"
That book, written after Ayer had studied with some of the Logical Positivists then active in Vienna, begins with a chapter "The Elimination of Metaphysics". Here, Ayer maintained "that no statement which refers to a 'reality' transcending the limits of all possible sense experience can possibly have any literal significance".
Collingwood wrote his Essay on Metaphysics (1940), and his rebuttal of Ayer features in chapter XVI, "Suicide of Positivistic Metaphysics", which appears to rest on RGC's theory of absolute presuppositions.
Many years ago (around the time Ayer was writing Part of my Life, in fact), I bought a copy of Collingwood's Autobiography, which I still have. In the chapter "Question and Answer", Collingwood outlines his departure from conventional propositional logic, with the view that any proposition Is in fact an answer to a question, and should be considered in that light. In the Essay, he says "Every statement that anybody ever makes is made in answer to a question"; and also "If the meaning of a proposition is relative to the question it answers, its truth must be relative to the same thing".
I'm not now convinced by any of this. While the context in which a proposition occurs may be useful in understanding its meaning, and perhaps the reasons for its being stated, its truth will be independent of this context. The laws of motion formulated by Isaac Newton were accepted as science because they fit the facts, quite independently of the story about the apple in his orchard. Or indeed anything else about Newton's life or the society he lived in.
I enjoyed Ray Monk's biography of Wittgenstein. However, I think the view in his Prospect article that Collingwood's early death altered the course of British philosophy is stretching the facts a bit. In my view, Ryle was influential principally because he was an operator, not because he held a particular Oxford professorship.
Even if Collingwood had lived on and the vacancy not occurred when it did, Ryle would certainly still have written "The Concept of Mind", and possibly also been appointed editor of Mind, the pre-eminent British philosophical journal. I don't think Collingwood was an influencer on that level. I see him as a bit of an outsider: his influences were not local thinkers but Italians (Croce, Gentile), so he was not part of any Oxford faction. As far as I know, he left few followers to advocate and develop his thinking. Contrast his contemporary Wittgenstein, who also died early, but left a small army of disciples -- Anscombe, Geach, Rhees, von Wright, Malcolm etc.
Of course, I could be wrong about that. It is true that, 80 years after his death, quite a lot of his work is still available, in print or as e-books. I'd be interested to learn more about any influence it has had.