OK, so I've figured out how to recreate this. I've done this in AC11 and AC12. I started with a default AC Template. The steps are as follows:
In plan draw a wall within elevation boundries,
Place a window in that wall,
Drag a copy of the wall/window, place next to original,
Open elevation window looking perpendicular to the walls (I used North),
Highlight windows, in settings check "Label Window",
Back in plan, drap the copy out of the elevation boundries.
Drag that elevation onto a layout. If it does what mine does you will see the original wall/window/label and you will also see the label associated with the copied wall/window even though the actual elevation view doesn't contain the label of the copied wall.
If someone has a few minutes I would be interested to see if you come up with the same results.