what a bunch of chior boys, no good deed goes unpunished. don't look a gift horse in the mouth. why is its someone else's responsibility for trying to pamper to someone else's needs if they were dumb enough to lose something in their possesion? How about the party that commits the error takes some responsibility for their actions?
Now if the property was stolen and not found that I agree that its messed up, but if you find something that someone left behind keep it. If you found some spanish gold in Florida or something, would you try to find the rightful owner(who's dead) or keep the bounty for yourself and the people that helped you discover the treasure?