Lying is Neutral Good, but the source of that particular ability is Lawful Evil.
Getting it was not pleasant.
As for the petrifying gun, most if not all flesh-stone effects seem to be based with a Fortitude save to negate it. The most powerful in spells being Flesh to Stone, with a minimum DC 19. Lying's base Fortitude save is +14, so it shouldn't be all that effective, though more effective than giving him a major headache.