Does it matter? We assign causes after the fact, quite arbitrarily sometimes.
Can't it be both? It doesn't have to be an either-or situation. He made a choice, and then assigned blame--err, causes.
I suspect the brain imagines a virtual self and imagines the virtual self having made choices. The brain justifies the actions taken after making an automatic response to complex stimulus.
Our consciousness is the brains awareness of the virtual self it created and imagines I suppose in control and at cause in life. The virtual self has choices and "freewill" to act. The brain identifies with the virtual self. The brain says this is who I am. But the self has no real existence. The brain exists. The brain reacts to stimuli.