This title is super weird. Yeah this person was a mnemonist, and yeah he died. But the article is not about the "the death of a mnemonist". As far as I can say

This title is super weird. Yeah this person was a mnemonist, and yeah he died. But the article is not about the "the death of a mnemonist". As far as I can say he lived a long life and died at old age. There was nothing special about his death. It was not related to him being a mnemonist. (or if it did, the article does not try to make that connection.) It is almost as if they had a simple article describing his abilities (perhaps titled "The Mind of a Mnemonist"? As the original case study describing him was titled.) And then just decided to spruce it up with a catchy title and some minimal attempt at mentioning his death.