As far as the clue is concerned, he also had Alex Trebek, who was pretty good at sniffing this sort of thing out. Bet you anything that clue doesn't see the light of day if Trebek is still around.
With all due respect, how do you see that going down? Maybe there's an interview with Alex I missed. Because that scenario would require his reading it in the morning and thinking, "Hey guys, you know this fact you said you double checked in this finished game we're taping today? Can you double check it again?" I personally arrive to a lot of material with a healthy skepticism, but if one were to look askance at that many clues in a game that's supposedly finished, that's one slow morning. (I'd be more apt to believe Alex wouldn't want to say it, but I don't think he'd immediately think it's bogus.)
FWIW, you see the type of attribution found in the problematic clue a lot without knowing it. It just happens in less potentially-harmful material. Complete hypothetical: THIS BOB SAGET SITCOM OF THE '80s & '90s HAS BEEN CALLED "THE SUGARIEST SUGAR TV EVER SUGARED". In this case "has been called" is a quicker way of saying "the writer found this funny sentence in one review or article." And nobody on high bats an eye, because all signs point to one correct response they expect somebody to say.
-Jason