Nina Mason: "QUICK: I say 'autistic person in television,' you think ... who? Probably Sheldon from Big Bang Theory or Sherlock from A Show Definitely Not Named for the Main Character. Neither is a good representation of autism, starting with the fact that both are very sarcastic men, and most people with autism cannot understand sarcasm."
Sheldon Cooper is NOT a "very sarcastic man." On the contrary, he frequently has to ask Leonard whether others are being sarcastic. Maybe I'm wrong - can someone here recall an instance of Sheldon being sarcastic? The closest I've ever seen is when he says something and then says Bazinga, but the Bazinga negates the essence of sarcasm. He says it as a way of pointing out, "yeah, I'm being contrary to reality for the sake of levity." That's how much he sucks at sarcasm.