Spoilers Crane an unreliable narrator?

I realize that just because he's on death row doesn't mean he's lying. We are hearing his side of events for the sake of the readers of a men's magazine. His lawyer, according to him, explained that facts are unreliable. Is this Ed's view? If facts are unreliable, as Ed chose to emphasize from his lawyer's closing arguments, then how are we to believe that Ed cherishes the concept of truth enough to deliver it to the readers? After all, everyone around Ed is an SOB. But Ed? Oh no not Ed. He doesn't even want a BJ from a 17 year old. He even confessed to a murder that was not his fault; self defense you see. But his lawyer was such a SOB he wouldn't accept it. Interesting thought experiment.