Wet runway, sidewinds, looong fuselage forward of MLG which has lots of wheels and weight.....could the relatively small, lightly-loaded (in comparison) nose gear have possibly aquaplaned?...especially as directional control began to re-establish, coincidental with reducing-speed.
when one looks at the complex tread-pattern of motorcars and the somewhat simpler, but deeperpattern on HGV tyres and compares them with aircraft tyres which are expected to maintain an adequate contact-patch and directional stability, at more than twice the road-vehicle's speed, it's not a huge leap of the imagination.
