When did US Warrants give a flying or other type fornication about a salute? In the day, Warrants didn't salute and didn't care about getting salutes.
US Warrants don't bow (or curtsie for the wimmin Warrants) for the Queen or her family either, so we don't expect them to bow or curtsie for US Warrants - but few would object if, in incredible awe, the Queen chooses to do so.
