It was the first episode of the Best Evidence series that also has examined such subjects as Bigfoot, The Roswell Incident, and Chemical Contrails. The TWA 800 episode was the first one in the series, and originally aired in January of 2007.
The episode will next air on the The DiscoveryTimes Channel on Christmas Day at noon EST. DiscoveryTimes seems to be having an all day marathon of Best Evidence.
The program also airs on the Discovery Channel, but there are no listings for the TWA 800 program yet.
So you did see the program, and it was on The Discovery Channel. It just wasn't an episode of MythBusters.
No. I distinctly remember the two “Mythbusters” guys, esp. the guy with the quasi-handlebar moustache. He’s hard to miss. Also, it was just the two of them, mostly, on camera. It was definitely “Mythbusters.” Sorry you guys can’t track it down, but it’s out there.