Crowded flight to FRA from ORD, we had to put one case and a heavy coat for grand-daughter a few rows in front of us as we boarded exit row 30 on a 777 a bit late in Y due to late inbound to ORD. When we got out our bags close to our seats, overhead, and started out, her case was there but coat was long gone from just 4 rows up....FA at exit row could do nothing of course. Lesson: do not put anything OH that you cannot afford to "lose" (weather on landing was blowing snow. Great that we were taking train from the airport station to Wien.