A diagnosis for when someone uses the wrong word or phrase when speaking but casually continues on as they don't even know they've used it incorrectly or that they've just made a new contribution to the English language. This is usually followed up with the opposite party involved questioning the word/sentence (silently at first to actually appreciate what just took place), but then typically followed up with public ridicule. This is much funnier when its someone in the spotlight. Sarah Palin and George W. Bush are notables who have suffered from this condition.
Sarah Palin on Fox News: "...the President and his wife - you know the First Lady - spoke at NAACP so recently, they have power in their words... They could 'refudiate' what it is this group is saying."
Pundit (silently): "WTF?"
Pundit (silently): "I don't think thats a word, but I better go look that shit up. If I even try to 'refudiate' that without the proper proof, Im going to be the one who gets 'Lynchburged'"
Pundit: "Oh yes, I see your point and totally agree with you (under breath: 'for now...you grammatically delusional bastard')"
George W. Bush: "There's an old saying in Tennessee... I know it's in Texas, probably in Tennessee... that says, fool me once, shame on ...(pauses)... shame on you. Fool me ...(pauses)... You can't get fooled again."
Listener #1: "Doesn't he mean the old proverb: 'Fool me once, shame on you; fool me twice shame on me.' ?"
Listener #2: "Yeah probably, but me must be suffering from a delusion of grammar again."