SPOILER WARNING> If you haven't listened to Chapter 24, then don't read...

I don't think "Hannah" is CJ...Kalani was only in the other tower for 3 days. He tells Michael so. I believe that Hannah was the girl the Mallers shot, as punishment for helping instead of hindering the Tower lot. She was expendable, and served the extra purpose of teaching Kalani a lesson. I believe that's also why he didn't hesitate in crashing...(spoiler spoiler).