Is the unconscious, as they define it, the compilation of habits and experiences gained throughout the course of our lives? If that's the case, it might be possible that, since these actions are reactive and quite compulsive, we may not have the full control of our reason when we commit any sins in this state (e.g having a quick tongue for cursing). It may only be a venial sin, and not a mortal, to take God's name in vain, so long as he is attempting to stop. Habits are not easy to break.