That's a truly epic fail, since Occam's razor is the strongest argument against the existence of God.

It's worth noting that the current formulation "entities must not be multiplied beyond necessity" is much more recent than Ockham's original formulation "For nothing ought to be posited without a reason given, unless it is self-evident (literally, known through itself) or known by experience or proved by the authority of Sacred Scripture."

I suppose that he included the reference to the Sacred Scripture specifically because he realized that without it, God would be the first thing to fly out of the window.