Back to the US Army psychiatrist: there were signals that this person was functioning badly and suffering from stress; but the organisation did not do anything about it. (BTW, what was race and religion of the Florida shooter, same day?)
Back to the security checkpoint. We have background checked security checkers, both the Muslim and the Anglican will have lived most of their life in Britain and "enjoyed" British education. Who of the two will be a bigger risk for the safety of my flight? (The Anglican can have a hangover...)
And when I am scanning my fellow passengers, I do see a group of drunk youth as the most likely threat to a smooth flight. Muslims don't drink.