When McCain was asked about the contribution of his running mate, Sarah Palin, he replied that she was a great campaigner. And then he rubbed his nose, covering his mouth as he did so. Then he rubbed his nose again. In body language, rubbing your nose and covering the mouth symbolizes covering up a lie. Children cover their mouths when they tell a lie; adults rub their mouths most often. Body language overrides what we say verbally, because it comes from the subconscious.
Take a look at the You Tube replay of the Concession Speech. You'll briefly catch a glimpse of that body language about 1:40 min.