Much has been made of the longer return to SIN, passing by BKK etc. However, if the damage to the machine and condition of fuel flow was the same, landing over MWL with nearly full tanks? There would have been a lot more fuel. All we know is that the mid-flight warnings were not serious enough to consider that and they had time to dump fuel. Given the fire on roll out, the correct choice. So it does seem that it's the last minute in roll out that caught them unawares.