What's really interesting about this scene, and its context...
It's clear in the flashback, that at the time, Plutonian blamed himself (check the look on his face, and how he's phrasing the narration)...but before he tells Charybdis this part of the story, he seems to have shifted the blame to Seabrook ('It wasn't my fault. They goaded me.')...I wonder if this came before or after he snapped completely...