Adam did not know that it was wrong to eat the fruit. Remember, the whole point of that tree was to give them understanding of what good (righteousness) and evil (sin) was. Adam did not know it was wrong, God intentionally placed an enticing tree in the middle of the garden, and instilled in to Adam his natural desires and curiosities.
Sounds like the only one at fault would be Yahweh, no?
That God is allegedly omnipotent and omnipresent makes God complicit in everything, especially the first sin. Yahweh completely facilitated their sin. In a court of law, we'd call that "entrapment."
Maybe God intended for Adam to sin. He wanted people to understand good and evil, and the best way to do that, perhaps, is to let people experience both punishment and reward. Just like a baby has no understanding of why we keep him from putting his hand on that glowing red thing on the stove. Once he does it one time, however, it makes a lot more sense the next time we tell him "No."
Think of God as a programmer. He makes a beta-version of the world and puts Adam and Eve in it. This allows him to work out any bugs in the systm in a controllable environment. He an program a lot of factual knowledge into Adam's head, transfer it into Eve, and even let them have some limited experiential knowledge. His intention is to then let them into thefull release version of the world, one with consequences for actions. It seems almost poetic to me to have the experience of movng from thebeta version to the full release version be te very experience that will help them understand consequences, good and evil, etc.