A rumor without foundation. All votes are eventually counted.
When you stop and think about it...they have to be. After all, there are more races on the ballot than just the presidency.
You are correct in saying that eventually all votes are counted. However once the margin of difference between the candidates exceeds the number of ballots yet to be counted on absentee and provisional ballots, the winner is declared. This is because even if all the remaining balance went for one candidate the one who is presently behind, in this case Hillary Clinton, there would not be enough to make up the difference.