Infinity is a mathematical absolute. It can be bounded conceptually, but the set of numbers is unlimited. Absolute power can by bounded conceptually (omniscience is knowing everything, omnipresence is being everywhere always) but the power is unlimited within those bounds. You can think of those as infinite knowledge, or infinite presence. Infinity breaks traditional logic the same way it breaks basic math.

So just as

infinity + 1 = infinity

{all known things by an omniscient being} + some new unknown = {all known things by an omniscient being}

Now, if you wanted to disprove something, the existence of an omnipotent, omniscient creator is inconsistent with the concept of free will. At the moment of creation, the being would be fully and solely responsible for all things that have happened, are happening now, and will ever happen. I don't like the idea that we can all absolve ourselves of guilt or responsibility by claiming "God's plan" and the just wank on while other people suffer unimaginable horror. Believing in God is an abdication of your place in the world, even if your faith guides you to do good works.