There is no definitive guidebook on how to pick the right partner, and even if there were, I'm way too dumb to write it.
I would say that the Pentagon Papers case of 1971 - in which the government tried to block the The New York Times and The Washington Post that they obtained from a secret study of how we got involved in the war in Vietnam - that is probably the most important case.
The timing of death, like the ending of a story, gives a changed meaning to what preceded it.