Continuity mistake: When Selina talks to Scarface in the limousine, her eyebrows change from black to blond back to black again between shots.
Continuity mistake: When Catwoman first encounters Batman during the flashback, her whip is coiled around her shoulder. When the camera cuts back to Catwoman after the shot of Batman, the whip disappears altogether.
Continuity mistake: During the flashback, Catwoman's whip disappears and reappears on her belt in a couple of scenes.
Continuity mistake: Catwoman/Selina gains and loses her pupils throughout the episode.
Answer: She escaped off-screen and created a copy of herself to fool everyone.