Eastway dances around the important issue which is what the viewer's expectations are versus what the print actually is, but never quite pins things down. He talks about, essentially, what the viewer's expectations ought to be, but that is not quite the same thing as what those expectations are. Simply asserting that since a print was in an art gallery that the viewer's ire is unreasonable doesn't actually help much.
That said, we are wandering slowly into a world in which everyone assumes that every photograph is a fabrication. In another year or two (possibly even now, but I don't think we're quite there) the vast majority of photographs will be fabrications, the output of a neural network into which 1 or more raw files were stuffed.
All the business about how every picture is manipulated is, ultimately, a distraction. Sure, it's important to realize that drawing a clear and firm line between fish and fowl is simply not going to happen here, but the fact that grey areas exist is no reason to declare the whole thing moot which is, honestly, kinda where he's going. He's slipped in a mickey by pretending that the only distinction that really ought to matter is whether a picture is a composite or not.
This is a difficult question, and I do not think that satisfactory answers will be forthcoming.