Then why are you acting so confused about parents who've said their experiences didn't match the account in the research study?
http://www.bmj.com/content/342/bmj.c5347
He DID lie about when at least some of the children's autism symptoms started. The parents have come forward and said so. And he DID have, at best, mixed motivations. He was being paid to achieve a particular outcome.
You can't statistically prove there is no link. All you can do is say you didn't find one. That's the strongest statement an epidemiological study can make. Anyone who's telling you different is misleading you.