Jim will, like every other inmate, lie if it benefits him. Strength of character has to be established for him to be honest. Diving into his mind without consent doesn't demonstrate the qualities he admires enough to be honest in confrontation with-- he might even consider your abilities cheating. You should speak to him on the subject.

Don't do it again.

I've spoken Arthas down from pursuing me, so try to keep from undoing my efforts. He isn't exactly easy to dissuade once he's set on something. Neglect to mention me at all, if you can. Do speak to him, however-- his head isn't on straight. It's a little...crooked.