When no foul play is suspected I only see 2 possible theories. Accidental or intentional. I understand that we don't get all the information that they have, but in this case they have enough to say that the possibility of either of those options seems very unlikely. IF anything I think it should be treated the other way around. The case should be open as something like "suspicious" unless they can prove that there was in fact, no foul play. Unless i see proof of any kind that can place him in a possibility that he could have fallen in the lake or proof that even gives us an indicator that he could have decided to end his life that night.........then something else happened. Because if you break down the information they have given us those two scenarios just don't . Make. Sense.