When everyone around knows that the "special" one is responsible for the event that recently occurred, yet someone still manages to defend said "special" person by stating how he/she is too innocent to do such a thing and/or how they have the mind of a child so how could they possibly think of such a thing to do. Also, doing this usually fails, or humiliates the defender.
Jury: *Unanimously* We all agree that (insert name here) is guilty for killing and mangling the woman and her two children.
Bystander: Wait a moment, am I not the only one who thinks he/she is innocent? How could such a sweet young man/woman do such a thing? Look, he/she has the mind of a 3-year-old. No 3-year-old has ever done this sort of thing!
Judge: Sir/Madam, sit down, or I will hold you in contempt! No 3-year-old has the body strength of a 450lb gorilla, either!
Man in Jury: He's/She's Pulling the Tard Card!