I remember having a big argument online with a guy that claimed to be an airline pilot, and this was absolutely IMPOSSIBLE, according to him. We got into all kinds of minutia, lifting surface, speeds, stability, and stuff. But if you look at it, there's plenty of bottom on the aircraft to act as a lifting surface should you fly it fast enough, and apparently that is exactly what this pilot did.
I never did convince this supposed airline pilot that it could indeed happen, even though it did indeed happen. He's probably still convinced he's right.