...contaminated fuel, maybe just water left: this could explain why the ultrasonic sensors signalled sufficient fuel in tank?
I cannot think of anything else for now.
A lesson: all runways should be like 27Left from now on. This incident could happen again. Same incident on 27 right at EGLL and the 777 would have found the VS Car Park. Slightly harder than the wet grass. RESA needed.
Let's move these car parks.
Well done to the crew, and maybe to the 777 autolanding system(!). Just kidding.