Those are his calculated odds for life as we know it existing. Those are not the odds of some life existing. If I roll a theoretical die with 1099999 sides, the odds are 100% that it will land on one of the sides. Any one possible outcome is equally as likely as any other.
To put it another way, if I shuffle a deck of cards and look at the result, the probability is 1 that they are in that order (after all, they are). The odds go way down to one in 52! only when I bet a priori on that particular sequence of cards occurring after a shuffle (actually, 7 shuffles to get sufficient randomness). But if I bet on any sequence occurring? Probability is 1.