I doubt it was quite that self-serving; it's more likely to be to protect Warden secrets.

If he had tried to convince Jory and failed, then yeah, but as it stands, I like the idea that he couldn't handle the possibility that Jory might live but not be a success, because of how badly it would reflect on him. I like having a reason for him to kill Jory without trying to change his mind, and this is a very interesting one! :)