Actually, she'd probably be a better judge if she did.

Rain Dampens Everything but Spirit - Los Angeles Times: "[Rose Parade Grand Marshal Justice Sandra Day O'Connor] told parade officials she was looking forward to doing the ritual coin toss to start the Rose Bowl game, joking that she would sometimes like to use the same technique on the bench."

If she used that technique, then statistically, about half of her decisions would be the right ones, which would actually improve her record.