I don't see that. Even if he were trying to hum it into the dirt, that wouldn't keep him from not pushing off his right leg as he did so.
But the more convincing evidence that he's hurt is that they only let him take four snaps under center and kept him in the pistol over half the game. And that's in a game they were never losing by more than eight points. That's not normal, and it's never happened in Cousins' career.
Looking at his other plays (Warren Sapp made a video of them), he couldn't move at all. That wasn't him just not knowing the system. Something is up with his Achilles.