I listened to this show over the weekend (if you don't listen to TAL, you should start immediately), and as I recall it, they were pretty unambiguous about the fact that people who routinely drank Coca Cola were, by a large margin, able to tell real Coke from this recipe.
The spokesperson ("archivist") they found from Coca Cola implied that stories like this come up all the time.
I don't suppose they had any original recipe Coca-Cola to test it against? It's hardly surprising that it would taste different since modern coke uses a different recipe.
Yeah. Modern Coke doesn't taste like my soft-focus sunlit memories of being six and having a big glass bottle of the stuff while wandering around the cavernous warehouse of the Contemporary Arts Center, but now that I've switched to small-bottler colas that're actually made with cane sugar, I get that taste-triggered Proustian nostalgia flashback on a pretty regular basis.
I don't see anything about carbonation levels. Dissolved CO2 has a unique taste and the amount contributes directly to the taste of the finished product.
The spokesperson ("archivist") they found from Coca Cola implied that stories like this come up all the time.