Nobody who's seen action in either the RAF or FAA has any axe to grind with one another. Apart from a few beers being chucked in messes and a piano or two being mercilessly burned to the ground, a flag being snatched from the stern, there is only quiet camaraderie.
And those in the know don't need to give a monkey's anyway.
Let's get this straight; the man is trying to sell his books.