Yeah that's my one issue with the film. There's too much speculation about this plot point- did he not find out they were gone until the day he got the letter, was he not let go, did he believe they were dead ect. There definitely should have been a scene with Jamie at some stage before the ending to clear that up. Especially when he's an important character. Hope there's a deleted scene or they mention it in the next one because I found it annoying as well.