The Count certainly doesn't call Childermass wrong in his assessment, so it's as good a guess as any. The way he addresses the group does seem to assume some crime committed on their part, that he is asking them to atone for.

"Your explanation is ingenuine," he says, tone especially cutting, just for Childermass. "You claim ignorance where there is none, and you leave out parts of the story inconvenient to your plea."