Before the cashier has a chance to do so however, the prospective robber has a heart attack and dies. Alternatively, the cashier is a stoic soul and simply ignores the robber, or shakes his head. The demand for money is a criminal attempt to impose a handle without the preliminary of a handle state, and the stoic cashier is mutating a handle to a signal in either case. Thereupon the would-be robber shrugs his shoulders and leaves. Then a handle has been issued by signals only.
Nothing has been spoken or changed hands, so there's no marker there either.
They haven't touched each other. While sitting out on his back porch in Texas, a war veteran noticed a large fly crawling up his leg, over-reacted, reached for his shotgun and proceeded to blow away the fly. The wound was so severe that he bled to death before medics could reach him. A real bank robber acts to his individual benefit at society's collective cost. A better, more basic example is two people who have the habit of exchanging nods whenever they pass.