That was a nifty little Tabeleau Mortant.
(Which is the name I'm proposing for the genre of 'look at static scenes of people dying, and figure out exactly what happened". It's like a Tabeleau Vivant (look it up) except everyone's dead.)
Case of the Golden Idol would be a Tableau Mortant then. Do you know of any other games that do the same?
Curse of the Obra Dinn.