Just waiting for the GOD CAN DO ANYTHING HE WANTS CUZ HE'S GOD excuses.

If sin is the violation of god's moral law, and god violates these same laws with impunity, then either:

1. The moral law is not objective but simply "divine" arbitrary authoritarianism, or
2. god is not morally perfect and therefore not qualified as a source of moral law.

Xtians want it both ways, arguing that a action deemed "sinful" for humans is perfectly okay if their god/gods perform the same action (e.g. genocide, infanticide, impregnating a woman outside of marriage - who was betrothed to another man).