I don't think he is a 14 as he didn't set out to intentionaly kill her. He didn't plan the kill. After he put her in a position where she would die, he left her there and tried to hide his involvement. That means he killed her simply because she was in his way. Had she lived, it would have been a sex scandal. Had she died he would have this drunk driving death hanging over him. So his plan was to run away from it altogether. His plan failed.
He did, in a self serving manner, scheme to get away from the problem to save his political ass. You are probably correct, it just sounded good.