If this is done well, neither Amos or Gavia is right. Much like the American Civil War was about slavery and wasn't. Depending on who you ask. If we could ask someone who witnessed the actual events leading up to the war, as an adult, we'd probably learn that things weren't so cut and dried. That the people who, supposedly, were only fighting against federal aggression really were into that whole owning people and using them to death. That the people standing up for human rights were motivated by economic issues, as well.
Of course, since neuroscience makes a strong case about how thinking about a past event isn't so much remembering that event as it is remembering the last time you remembered it, Alice may or may not be a reliable witness, either. It depends on what she is, really.
Of course, it could all be much simpler. Alice could be a perfect witness, Gavia could be the rube, and Amos could be the guy who knows what's up. It would definitely be an inversion of expectation, though a fairly typical one.