We find Grant like this a lot lately.
He has turned into quite the rolling machine. He's best at going back to tummy. He occasionally goes tummy to back but I think it's usually when he has momentum left from the first roll. He rolls in his crib a lot and then gets mad because he can't get back over.
It's looking like we're going to have another blue-eyed baby which is more apparent when he is surprised by the flash!