Caine does not condemn his friend Alethea with words. Instead, he lets himself be imprisoned and even lead to the gallows so that Alethea can discover the truth for herself. Here's where the episode loses me and maybe I'm just being dense - in the eleventh hour, she changes her testimony and saves Caine. Is it because she remembers the truth? Admits she didn't see clearly? This is never confirmed. The point is that Caine puts himself in the noose so that Alethea can state what is and isn't.
I wasn't crazy about it, and if you have another perspective on this episode, I'd be glad to hear it! Maybe our good friend Bobba has a perspective. One out of four yin-yangs. IMDB is here.