[Get-it-Correct]

Batter bunts ball. Ball lands, in fair territory, 12 inches in front of batters box. With the batter's first step out of the box, his foot lands directly on top of the fair ball (his other foot is still inside the batter's box. The rule states one foot must come in contact with the ground completely outside the box for the batter to be considered "out of the box". Since the top of a fair ball is not the ground, what's the correct call? Is it a dead-ball (just as if he came in contact with a batted ball while still in the box) or do you have an "out" for contacting a live ball while not in the box?