Italia,
Thanks for a good overview of the complexities of trying to get to grips with the way air behaves.
I think the author shunned Bernoulli's relation completely by making a revolutionary claim that I have never seen before. It is not one of the regular myths/misapplications that he is repeating. Here's my way of explaining what I think he was saying, and I have repeated his statement at the end:
Focussing on just the wing surface, ie its own map of local curvature variations and static pressure distribution that goes with the curvature.
Knowing the free-stream condition and a measured static on the surface you can calculate the vel at the same point using conservation of energy, ie with Bernoullis relation.
If we now drop a ram air turbine into the flow we can no longer use the relation for points U/S of the turbine and D/S because of the work extraction in between.
We can, of course, use the relation for all points D/S once we have redatumed, if you like, with a new lower total pressure.
Now, just as we say the whole of the lift force occurs from the wing surface pressure distribution we also say the whole of the energy transfer to the air also occurs only on the wing surface.
So energy is not conserved in the airflow over the wing any more than it was with the RAT power extraction.
"As energy is not conserved the Bernoulli relation cannot be applied to airflow round a wing in flight."
Nobody else throws it out for this reason. It's a new one as far as I can tell.
Can you make any sense of it?