People assume that because his technique is different that it is flawed and that he is ultimately relying on hand-eye coordination.
Not entirely true. He has a good trigger movement that gets him into a strong, balanced position as the ball leaves the hand. It allows him to come forward and go back with ease and he is also a 360 player with no discernible weakness. He drives, cuts, pulls and glances extremely well.
The text-book technique isn't the only way to bat. Ultimately it's about being comfortable, balanced at the crease and knowing your game.