So technically at his field it's not cheating. So I won't call it that, still seems a bit shady to me since I've always played that a player is not in play while being checked, but if that field is different then its legal, but maybe not the best thing to do. Sneaky yes, but not something I'm gonna blast a guy about.
Does seem a bit shadier than dry firing by turning your gun upside down and then getting someone when they expose themselves. Though that tactic doesn't encroach on any normal field rules that I can think of.