The Rock isn't counting down from three since Bad Blood. He's been counting up from one since WrestleMania XL Saturday.
People keep talking about what he has been counting down to but he's been doing the gesture (throat slit and the counting) since the tag match at mania last year.
He did the throat slit and threw the one to the sky at mania before hitting the People's Elbow and pinning Cody.
He did the throat slit and put up two fingers at Elimination Chamber before Cena turned heel and beat up Cody.
The final throat slit and the three count might probably come when Cena pins Cody and wins #17.