In UK atheists considred more moral than theists.

[Huggy Bear]

To be considered pedantic you'd have to be right...

Go ahead and explain in the scenario in which someone who knows every outcome of every decision would make a mistake.

That isn't what pedantic means, either.  A person can be nitpicky and still be incorrect.  Just as a being can know everything and still be a dick. Also, that being is not, by definition, also able to do everything, so they might not be able to take the action they deem "perfect".

So if a being knew every outcome but could not take all actions, that's a perfect example of your requested scenario.

I clearly stated:

God is omniscient, which by definition means his decisions are always perfect, they cannot be improved upon.

We're clearly talking about decisions that are MADE, so what exactly are you talking about?

Or if they knew every outcome but desired a negative outcome, that's another example of your requested scenario. 

Now if you pair omniscient with omnibenevolent and omnipotent, you might begin to have an argument, but then we butt up against the problem of evil.

But yeah, you can't just toss out one of the three and act like it covers the whole gamut.  It doesn't.

Doesn't matter, If you were an malevolent, omniscient being, and desired a negative outcome, you'd still know the best way possible to make it happen.