I wish I could reprint or reproduce the article here...

According to the article: ( and I'm paraphrasing as I write this ... )

The pressure differential is insufficient to achieve the lifting forces. When measured the change in pressure is miniscule compared to the amount of lift that results.
The article goes on to say that it is the rotational vector itself that causes the lift, not any pressure differential.

Several practical test examples are given, which are pretty convincing...