I see that somebody wanted to know.
There was nothing untoward about his death, or at least none that is known. Yes, his handling of John Paul I’s (#264) sudden death drew a lot of criticism in 1978. He also took a lot
heat related to the logistics of the two 1978 conclaves — the largest conclaves, in history, in their time.
Yes, it is also speculated that he, more of a ‘liberal,’ was not that enamored with the election of the ultra orthodox John Paul II (#265). As I document on pages 199 and 200 of ‘The Next Pope‘ book, it is claimed that he orchestrated two incongruous ‘comfort breaks’ during the October 1978 balloting — thought to be to enable the ‘progressive’ cardinal electors a chance to rally their support and foil the election of Karol Wojtyla.
But, John Paul II appeared to have held anything against him. He was reappointed Secretary of State and was retained as Camerlengo. So it is hard to come up with a conspiracy theory that says that he was dispensed off — because of his ‘liberal’ leanings.
His heavy smoking was legendary. He is also said to have been a workaholic. Bronchial Pneumonia, probably exacerbated by his years of smoking, makes sense.