I take back the day 11 part, I'm not sure what day it is. And if anyone wants me to link the post, just tell me how to do it.
What I have read (as I have never had a shipped egg, or an egg with a detached air cell), is that you have to make sure you are turning the egg the right way to get it to go where it should. All air sacs, I believe, start in the fat end and only jostling and such will get it to be anywhere else. When it is, you've gotta convince it to move to where it should be. So, fat end up, gentle regular turns (either in a turning tray, or by hand). Mark the egg with X and O on either side, and rotate regularly, keeping fat end up (if no turning tray, then by using egg cartons). The sack is outside the membrane, so the process of getting it to go from tip to fat end means separating membrane across the length of the egg. The membrane is attached to the shell so it can breath, and detaching it from the cell is not a healthy thing, unless done slowly.
If they did not notice this till day 11, they've never done shipped eggs and haven't read anyone's advice about shipped eggs...so, it is what it is. At Day 11, ideal weight loss is nearly 1/2 of all weight loss, and air cell development should be roughly equal. Its much harder to get a big air cell to move than a small detached one. I have to believe theirs has re-attached to the shell, albeit in the wrong place.
No advice from me, just what I think I have learned from what I read. Sorry