Crab.
Look at Jymil's post #15. The streamlines ARE deflected down. They are at least 1/2cm lower on the right than the left.
Why would accelerating air downwards create a downward force on the wing ? Is that what you observe on a pool table or in a rocket engine ?
Your point about the underside of the wing is absolutely correct, but the point about Newtonian mechanics is that they do not attempt to deal with why or how the wing does what it does, which part of the wing does what, and less still the best shape to achieve it. They simply describe the aggregate consequences of it.
You can still have long arguments about how the wing actually achieves the acceleration without calling into question Newton laws.