WARNING: This achievement is partially unobtainable. Some people are still able to somehow unlock it while for others it remains locked even after completion of the episode. Telltale is aware of the issue but they have yet to fix it.
UPDATE: So I just rewound Chapter 6 and it popped the second time around. I made mostly the same decisions except at the very end I decided to side with
instead of
Not sure if this made a difference but there you go.