What kind of makes me doubt the validity of this story is the "refused to meet his contestants before the show" part. Don't the VAST majority of American game shows prohibit hosts from doing exactly that?
And also the part about how it would look "on camera." Stand at profile, a reasonable distance from a mirror, put the hand not facing the mirror next to your mouth and then put it on your shoulder. That's enough distance that you'd see the difference.
Besides that, eventually, this kind of thing would make it into the press somehow. Everybody who comes to Hollywood from out of town and appears on a game show winds up in their hometown paper for it. In the course of researching my books, I've already had to read one contestant's account of how Allen Ludden was a snob because he didn't make eye contact during a commercial break. The mouth tear would have been written up somewhere, and honestly, it probably would have gathered steam because that's such an aggressive thing to do.
