So after looking at a few of your replies. I see that you value human life over other forms of life, my question here is: Why do you value human life over other living beings? Also, I believe you are confused on the definition of murder. The man and dog would have both died of their own accord had you not been there, so the fault is either on them or whomever caused them to go into the water. In addition, legally you are only required (in some areas) to assist if you yourself are not put in harm's way by doing so. In other areas, there is no such requirement. Either way, it would be manslaughter, but in this situation, there is no way in which it would classified as such.