Just booked a flight in J on a 777 for my disabled son (he's 20). He has a window seat, his attendant (my wife) was given the middle seat beside him (allocated by AE; the process is that I book his ticket online, then call AE to get the attendant's ticket booked). I had expected her to be given the seat behind. I'm not worried about it, because when I book my seat in the next few days I will take the seat behind him, assuming it's still available.