[edit]
I was imperfectly remembering the rules. If it is theoretically impossible (even with blunders on the player who is out of time's part) for the player with time left to win, then it is a draw.
In addition, a player with less than 2 minutes on the clock may request a draw; see Article 10.2 which includes this subsection:
> a. If the arbiter agrees the opponent is making no effort to win the game by normal means, or that it is not possible to win by normal means, then he shall declare the game drawn. Otherwise he shall postpone his decision or reject the claim.