We have a 7-year-old daughter who suffered TBI when she was ejected from a vehicle at ten days old. Even though she is a people person (friendly, conversational, and very, very affectionate), she exhibits enough autistic behaviors (inability to play appropriately or imaginatively, hand-flapping, no eye contact, displays extreme distress for no apparent reason) to keep me thinking about the similarities. She has made a dramatic recovery from her original prognosis ("This child may never walk, talk, or see."), but she is still years behind her peers developmentally.
I have never bought into the vaccination theory. (I have a nephew with autism who's never had a vaccination of any kind.) Since entering (and embracing!) this sub-culture of special needs kids, I have often wondered whether autism is not just another form of injury to the brain. Perhaps there is not "the same level of contentiousness" surrounding TBI, because parents of children with TBI can point to a specific cause of injury -- something to blame. With autism, I imagine that most parents want/need SOMETHING to blame -- thus the contentiousness and thus the vaccination theory.