Notwithstanding the fact that fuellers are unwilling to resell fuel that has been offloaded, at carriers' home bases, I could envisage centre tanks being emptied entirely prior to refuel as a result of this, though greater fuel line heating throughout flight may be the answer.
They will not resell fuel because they don't know what it is. It may come out of an airliner tank but it will be a mix of Jet A and Jet A1 and even Chinese fuel. So they give it back to the airline it came from.
Centre tanks are always empty before refuelling starts. Do you envisage someone removing the dregs?
I find myself staring at a figure for water (138 gallons in the centre tank alone!) more than two orders of magnitude larger than the the 5 litres (40 ppm) quoted in the AAIB report, yet "acceptable" before an EICAS advisory message is triggered?
I believe the B777 was the first aircraft to have a built in water detection system. The reason for the 138gallons is that the bottom of the centre tank is flat. This is why the boost pumps are switched off with 800kgs remaining, and the rest sucked out by the jet pumps,
In hindsight perhaps Boeing should have made the EICAS message a Status message which the pilots could see.