While the monk strained to make his reentry, the monument gem, powered by Hal, continued on its path of conquest over the Monument of Ordinances.
It is indeed true that the Monument of Ordinance is a creation of Order and is also powered by Order but the level of might that it has been apportioned is nothing in comparison to the overall might of Order itself.
This a natural flaw in the Monument's design because while it was a creation made by a primordial concept, it was created at a time when the concept had been weakened.
True, it was a divine artifact but it was still at a range that Hal could very well manipulate.
Take the Primordial Cosmic Grimoire for instance;
It had been created by Chaos through its Avatar, Primordial Will and Hal was still able to override whatever control Chaos had over it to turn it into his codex.