@ThinkPositive— The reason that I italicized the “if” is because, at present, there are two possible interpretations. It is
possible that he directly killed his father; it is
possible that he merely feels that he drove his father to his death.
But understand that, within these possibilities, there are sub-cases. For example, perhaps the father pulled back from killing himself, only to be killed by the therapist who had been attempting to manipulate him. The death is not then a patricide or a suicide.