There are a couple of conditions for that to happen (I had to look at the walkthrough). Was surprised as DFD hadn't really done that much or asked you to go so far back up to this point, and it was always something that annoyed me about DMD -- it would be even more of a headache with DFD's save design.
Yay chapter 12.
But I think I played the last several chapters up to 11 "online", so this offline one doesn't recognize my 11 backup, so I'm stuck.
Eit: Oh, hey, there's an Online one... [tries]
Update now that I'm back on the computer -- yup, that worked. (lights cigarette) It woooooorked.
You'll love ch 12, trust me.
I'm... not quite clear on what I was supposed to love about the chapter, Amanda-wise, as there was very little interaction with her and most of it was cold. Unless I missed something.
Also, finally and a bit out of nowhere, the player character finally drops the fact on the player that he does have a secret. After a couple of chapters of "what could this be about" on his part too. Long-overdue, but kind of annoyingly clumky.