From page 28:-
"If the rain had just moved in, the runway surface could well have been more oily than wet.
The top part of pavement is full of petroleum-based products, mostly microscopic bits of tyres. When it first rains after a dry spell, those oily bits of petroleum float on the surface of the just-fallen rain, and that is when a paved surface is the most slippery. This is particularly true on those areas where the tyres are accelerating, decelerating, or turning (because thet's where they shed the most rubber). After it has been raining for a few minutes, the water/oil ratio grows large enough to eliminate the oil surface, and it's just a question of a wet surface."
The above situation is 'normal' (given the conditions) and shouldn't be a surprise to any transport driver. What isn't normal is a sudden reversal of wind direction or a sudden cloudburst. An earlier posting by a jockey described extra flaps and a 'determined' touch-down, which sounded good initiative (and common sense). Maybe a combination of that jockey's technique and a better touch-down location towards the runway threshold would have saved the aircraft, though there is still the combination of possible deep water causing aquaplaning (on a non-grooved surface) and the aberration whereby aerodynamic retardation devices might not deploy due to the dynamic parameters of the undercarriage. I believe passengers reported a reduction in deceleration after the initial braking phase.
It might not ALL be driver error . . .