Winston put the WR in motion, then called for the snap before letting the WR get far enough down the line to be past the play.
I guess it's possible the WR should have motioned to be near the TE instead of running across the formation ... but you'd hope Winston would have waited long enough to make sure the WR was doing what he expected before snapping the ball.
The more likely scenario is the WR was supposed to sprint across the formation and be close to even with the center as the ball is snapped to make it look like a possible direct snap jet sweep to the WR in the hopes of getting a LB or two to run the wrong direction before the handoff up the middle, but Winston accidentally the whole thing.