I think chatter is putting it mildly. There's plenty of evidence in this work [1] that is hard to explain. At the very least it's a failed attempt at benchmaxxing the model, but more likely is straight up training on the test set (and the attempt at hiding it failed). Something leaked pretty heavily in their setup.
And there's indications of it happily replying with fake encrypted data in oAI format here [2]. While this is a bit less conclusive than [1], it's still dubious.