Continuity mistake: At the diner, before Mrs. Duncan comes to confess about murdering her husband, Brennan takes a sip of tea. Her glass at this point is less than half full. When Mrs. Duncan walks in, the same glass is now almost full.
Other mistake: At the start, when Hodgins gives his findings at the scene a fly can be seen crawling over the camera lens. (00:02:00)
Answer: Since the palatine bone is a bone that helps form the mouth it has a lot to do with speaking. The shape of it differs a lot depending on your ethnic background. I would guess that they, in the show, meant that the person's bone tells that they were Japanese and that it was "made for the purpose of speaking Japanese." That's what I'd assume anyway. I've studied molecular biology though, so I'm not an expert on bones.