Also, if you did the daily quest, the honor received from turning in the quest is incorrectly added to your estimated honor twice (once as soon as you turn it it, and again a few minutes later.) This means that (as a level 70,) you will always have an extra 419 estimated honor when you complete the quest that you did not earn.
Also, the estimate does not take into account diminishing returns from killing the same player repeatedly. If the estimate is 20 honor per kill for a player and you kill them 5 times, the estimate is 100 honor. However, to avoid kill trading, the game reduces the amount rewarded from repeat kills and this accurate amount is used at the end of the day in rewarding honor.
Therefore, you're not really losing honor, but just not being given an accurate representation of what you've earned until the next day.
What was said about the couple hours before the rollover is also true, you receive that honor on the following day.