I've become convinced that Moore was looking at a mid-season transfer, but he wasn't able to get it done, which is why he is back now (there are schools that don't start until mid-late Jan). Pastner was letting him explore options and now it's in Moore's best interest to remain in school for eligibility and on the team (even if he doesn't see the court) for development and look to transfer after spring semester.
This squares up with Pastner's comments (eligible, not injured, personal decisions, etc) and explains some of his complete absences.