I heard on the news yesterday that long haul flights are having to make un-scheduled stops to top up their fuel tanks. Having heard that they had more than enough fuel, I think that it is more likely that the short fill the tanks in the UK and are topping up in countries where the fuel is cheaper. They can then blame it on the depot fire and hope that the passengers will understand. Fuel being one of their highest costs on a flight, they stand to save quite a lot of money by fueling overseas.