If it IS vinyl flooring, it isn't from the kid, it's from pregnant mom, I think.
Although we didn't have vinyl floors (and because of insurance screw-ups, didn't get my son properly vaccinated well until after he was full blown autistic), I was exposed to a lot of toxins (airborne) during my pregnancy.
But the interesting thing is, in retrospect, he had signs of autism almost immediately after birth. Part of autism (which he has to the point where he cannot speak, and most likely will never live independently) can be sensory problems, and his are oral/eating related.
He would not breastfeed. He would not take food from a bottle. He could not leave the hospital for two weeks because of this. Even when he got home, formula or breastmilk would pour down his face as much as it would pour into his mouth.
I've spoken to other parents who saw signs, small ones, very very early on. Yes, my kid did have a bit of that 'developing ok and then all of a sudden went backwards' stuff, but he was already a bit off, I think. And he still does that today -- over the summer, without school, he lost the ability to communicate completely. It's just that parents seem to notice that first change.
So vinyl floors? A bit of a reach. Something happening during pregnancy? A possibility. Toxins? A possibility. But my wood floors didn't 'save' my son.