I think I know what you're thinking, partially because you're me and partially because I felt the same thing when everybody blamed my future self for the Coyolxahqui incident.

Sexby is a human. And, even though he is a warden, I feel this ship drives wardens as mad as it does inmates. He's trapped in this prison as well, with nothing to do but redeem an inmate and dwell on his emotions-and you know how horrible humans are when dealing with emotions.