You'll have to take this with a grain of salt until we get further confirmation: the epic flying mount is obviously bind-on-pickup, and so it's not like such a thing can just be thrown on the AH for the highest bidder. But it could be that the guild the mount dropped for somehow sold a raid spot, or it could even be that one guildie paid another just so they could have it (someone in my guild did the same thing with Attumen's mount when it dropped, although it was far less than 190k gold).
But that is definitely a mind-blowing amount of gold. I'll leave it up to you to decide whether it's legit (by my calculations, it's not-- to collect that much gold, a player would probably have to be running their 10 daily quests for years), and also to decide whether or not it was worth it. Guess he just really, really wanted a mount without feet.