Shaq took every chance to bash him, which was kind of childish. But that's Shaq, he's not afraid of controversies. To make his points, Shaq said many times that only Yao Ming and him are real centers in the league, which was true. And he went on to boost Yao Ming's skills to dis Howard. But if there is no DH13, Shaq in his prime wouldn't have even looked at Yao, he will 完爆 Yao Ming every single game.
Let's not forget, Orlando Magic led by the young Shaq, was swept by Dream led Rockets in the 95' finals. But Shaq still averaged 28 points per game.