Did they say they smoke real cigarettes or electronic cigarettes ? I doubt it is real cigarettes. You do know that if it is electronic cigarette, basically anyone no matter crew or pax or and race use that on the plane now as no one would smell anything (basically any cigarette smoker would have a electronic cigarette now in order to smoke in the plane and non-smoking hotels including myself, we can smoke anytime as long as no one see it, don't even need to worry about smoke detector), so your point is irrelevant compare to OP's friend actually smell real cigarette smoke.