2 the fuel state only became an issue when it appeared that the contents of one tank became unuseable and that was only noticed towards the end of the flight and did not manifest itself earlier on as the tank was behaving properly.
Exactly because of these unexpected problems, one might consider better to be safe than sorry? This time it's at the end of the flight, what would have happened if something occurs 2-3 hours before the end of the flight?
Interesting theory DingerX, but didn't you forget the factor hamburgers sold on the mentioned airports?