No, what is being parroted, by the NIP, and the Industry, is "You can't prove it" ......
And I notice you are confusing two separate issues here. There are separate allegations. One is that a vaccination, specifically the MMR vaccine, causes autism. The other is that the preservative thimerosal causes it. It would be wise to differentiate the two.
That, is also erroneous, I clearly explained the case of the MMR, and its link to thimerosal. Those issues are cojoined.
Let me restate, the MMR vaccine never, EVER contained thimerosal.