He would need something like 68% of all the absentee votes to win. Its not statistically possible (though mathematically plausible) that the absentee voters are 50% more likely than regular voters to vote for him.
Actually, it's very possible. The kinds of people who do absentee ballots might be military people - in which case they might vote 70-30 for Sullivan. Or they could be people from the remote areas of the reservations, in which case they might vote 70-30 for Begich. I'd say there's a good chance Begich might still win.
They’ll probably find a voting machine in a closet somewhere that has uncounted votes, or about 20,000 uncounted “ballots” in the trunk of a car belonging to a poll worker.
Happens all the time....