He should have still gone to jail. He did "attempt" to kill her and, if it wasn't for the glass near her bed, she would still be alive. He provided the means to kill her. In my book that's premeditated murder. Of course he could have blamed it all on the quack doctor.  Not a believable ending. So he decided at the very last second to let her live because he wasn't cut out of the will, big deal. Next time, throw out the milk if you really mean it!!