And the woman said to the serpent, “We may eat of the fruit of the trees in the garden, 3 but God said, ‘You shall not eat of the fruit of the tree that is in the midst of the garden, neither shall you touch it, lest you die.’”
God never told Eve that she could not touch the tree. Eve added that. But when we defend God by adding to His instruction, we actually take away from His authority. It's called subtraction by addition. We give the serpent a crack in the seal into which he inserts some dirt into an otherwise pure environment.