In any case, your new question is irrelevant. If Adam has an infallible brain, then his choice by definition was correct, and we now have the fallible brains god intended. So no difference between that, and god just creating originally with fallible brains. Bad luck - another diversion fails at the first hurdle. What do you know about what God intended or not? Did you ask your priest?
That's another lie that atheist want people to believe. They want people to think that God purposely do bad things, that he "wants" us to fail.
That is wrong.
Let me take you through it slowly then.
Option One: god created Adam with a fallible brain. Conclusion: god wanted man to have fallible brains.
Option Two: god created Adam with an infallible brain. Therefore, whatever decisions Adam took were perfectly correct, and exactly what god wanted him to do. If those 100% correct decisions then led to him changing to a fallible brain, then god must have intended that to happen all along.
Conclusion: god wanted us to have a fallible brain, whether we were originally created that way or not.
If you disagree, you need to show how an infallible brain, created by god, could lead to a fallible brain, without god intending that to be the case.