https://people.com/tv/wheel-of-fortune-host-pat-sajak-accidentally-gives-away-answer-during-on-air-slip-up/

"Yikes," he said during Thursday's bonus round, after only six of the puzzle's 12 letters were revealed. "Well, I'd rather be standing here than there, quite frankly." Turn out "quite frankly" was the answer to the puzzle, though the contestants got the answer wrong.

OK then. Burt Convy did that more than once hosting Super Password.

Ed.

Probably the contestants couldn't understand what Pat was mumbling, otherwise they could've done the Super Password routine with the host duct-taping his mouth. :)