You'd have to be (a) a complete twat, (b) absolutely certain that her driver isn't 6 foot 6 with a baseball bat, (c) not doing an outcall at your own home and (d) absolutely certain that you are completely untraceable. But mainly of course (a).
if she calls the police and tells them that not only did you refuse to pay, but also threatened her with violence or worse, who's to say they'd believe you over her? She's done nothing illegal and as the victim she would be entitled to anonymity, whereas you wouldn't. Worth taking the chance?