I hate to beat the Mary/marry/merry dead horse still more, but this reminded me of a time a few years ago the same discussion came up on a forum I was on. Around the same time, I caught a rerun of 3rd Rock from the Sun, in which Dick and Mary, who were engaged, went to visit her family during the winter holidays. So they could talk about Mary's plan to marry, and wish each other Merry Christmas. I tried my best to hear if they pronounced any of those differently, but I couldn't. But then, maybe it was in character, as they were aliens posing undercover as Earthlings from Ohio.
But regardless of whether we agree with the Jeopardy! judges' decision or not, can we at least all agree that there are people, generally depending on where they live, who hear and pronounce things differently from each other, and it's not due to some kind of basic ignorance or character flaw?