If you are referring to the Edgar Allen Poe story where that one guy kills the other guy for his creepy glass eye, then I can help you. Yes, his opinion of himself does make him far less trustworthy stacked up to the later events and even the previous events of the story. the man is most certainly more than mad, physcotic in fact. The fact that he doesn't recognize the madness of his actions moves him from untrustworthy to absolutely insane.