I don't think the force of the wind hitting these trees makes them 'windswept', but the continuous push of the wind sure does. These trees are constantly being pushed one way, and so end up just going with the flow and growing that way.
one might want to see is the windmill lodged in the top of an Oak that wound up there (as the story goes) from a hurricane back in the 1920's. It's located in a tree in the front yard of a house one street directly behind the Fulton Mansion.
The large branches have forever wrapped and wound around the wooden fan frame and blades making it a permanent part of the tree. It's unbelievable to look at and imagine how it got there. Some say it flew all the way across Aransas Bay from St. Joe Island. Check it out next time in my favorite town in the world. ComeFrom?
Actually I found a site that talks about it. I'm right, y'all are wrong Well y'all were partly correct.
"Trees closest to the ocean are subject to onshore winds carrying sand and salt spray, which acts not only to prune terminal buds in the canopy top, but also encourages growth of lateral buds, producing over time, the familiar windswept shape of maritime forest canopies."