Radak #1: If He [saw and] knew, He forgot.

Radak #2: He does not know at all. This is like one who forgot a matter and does not know it, or like one who knows a matter and hides his face and wants that he will never see it.

Malbim: First the Rasha says that even though He sees and supervises, He forgets to punish immediately, and therefore no decree comes quickly for an evil deed. Afterwards he is more brazen, and says that Hashem hid His face and does not supervise lower beings, for His honor is above. Then he is more brazen, and says that Hashem will never see, for sight and knowledge [of the lower world] do not apply to Him, like philosophers claimed, like Moreh ha'Nevuchim brings. The Rasha descends in three stages, based on the three stages of his life (refer to 10:8:1:1), until he denies Hashem's knowledge.