GP was not disputing the redirection of flow or the magnitude of force/air momentum change. They were just saying that not all of this is because of the "scoop"

GP was not disputing the redirection of flow or the magnitude of force/air momentum change. They were just saying that not all of this is because of the "scoop" effect from the bottom of the wing: a significant part of the redirection also comes from the low pressure above the wing (at least in practical cases).