What he said is an absolute truth. Momentum conservation is a fundamental law of nature, and if the air is exerting a upward force on the wing, transferring upw

What he said is an absolute truth. Momentum conservation is a fundamental law of nature, and if the air is exerting a upward force on the wing, transferring upward momentum to the wing, the wing is transferring downward momentum to the air. "Transferring downward momentum to the air" is pretty much the definition of "throwing air down". There is simply no way around that. But it says nothing about the how a wing is throwing air down.