It did seem like a coin toss at the time

Only for those who went by gut feeling instead of closely inspecting the tarmac they were literally standing on.

There are low tech means to figure our how wet even the pores are, for example by blasting compressed air onto the tarmac and hold a piece of cardboard next to it to catch droplets. That's kinda (minus the cardboard) what Nascar do to dry tracks because somehow in America they know that there is residual wetness in pores and the pinnacle of motorsports doesn't.