Unless the Dwarves were absent for an extended period, it seems doubtful that they would fail to smell the fumes from a rotting corpse so close to their encampment as the dead courier decomposed.
And by time, I was referring to the amount of time that has passed between the sending of the message and its delivery which entails a presumption that the sender feels exactly the same as they did when the message was sent out years ago.
It was not a reference to longevity of life, just that most things and positions tend to change over time and so might the original basis of the treaty. Not that it can't be presented, just that we can't ensure that it still relevant and accurate.