If you stay on the balls of your feet instead of being flatt footed and you really push your center up, you can come back up easier. Sensei likes to use me to demonstrate and I get put in that situation so he can demonstrate why you should stay on the balls of your feet (for the sole reason you mentioned- you can come back up or walk around backwards if nage decides to walk you around)
its all about the balls of the feet. lol
Staying light is usually one of the biggest priorities we are taught in my school. Connection and lightness, they allow for you to maintain your ballance, and recover if nage leaves an opening.