We've seen plenty of game show contestant fails.  It's not always on the contestant though, sometimes it's the game show staff.
We've seen bozo's blow the Wheel Of Fortune puzzles when there's only 1 or 2 letters missing. I remember one dope who couldn't guess the names of the seven dwarfs with practically all the letters in place.  How freakin' obvious can they make these things?  A recent Jeopardy episode had two of three contestants wind up with negative balances. The screw-ups aren't always on the players though.

This totally hot Price Is Right model accidentally gives up the price of the car ahead of time, giving away the win.  Luckily for her, Drew Carey and the show's producers are pretty understanding so, she didn't get in trouble.

Maybe not with the bosses but the audience sure got ticked off.