Brick Walls, Moral Facts, and Mental States: How to avoid the fallacy of composition

In the case of the brick wall, the state of the bricks entails the state of the wall, therefore it is the fallacy of composition to say that since the wall can't be six feet tall because none of the bricks are six feet tall. With the question of whether a homicide was morally justified, the physical facts don't entail the moral fact, so you would not be committing the fallacy of composition by claiming that no moral fact is entailed by the physical facts. I was claiming that the problem of mental facts is like the moral case, as opposed to being like the brick wall case. When all the facts at the physical level are given, the mental fact is still an open question. But since the state of the physical is supposed to close the question (what else is supposed to close it?) of the state of the mental, saying that there might be no mental given the state of the physical does not commit the fallacy of composition.