As the taxi runs into a lamp post, Jessica and Hoskins are both thrown from the car; Jessica lands spinning, which causes her red dress to start hiking up her body.
This scene can indeed be seen on the home video release and was clearly intentional.
Here, she is one of several suspects in the framing of her husband, who is a famous cartoon star.
Animators have traditionally amused themselves by slipping occasional racy frames or other gags into their work, frames which flash on the screen far too briefly to be detected by theater audiences.