It isn't that there are separate panels, they just run a cable to each part for distribution, space, and any number of reasons. I have encountered many LCD screens with this problem. No difference between an LED backlight panel and a CCFL backlight panel other then the backlight technology and power supplies. More modern panels with local dimming and other features are getting a little more complicated, but still somewhat repairable as long as the screen is intact.
Anything can become dislodged with the right application of force, and you are assuming they clipped and attached it securely. More often then not a little bit of caulking/glue is used to prevent connectors from backing out. Many QC tests will let a bad connection pass if it is making enough contact at the time of the test. (I doubt they are impact rated, they assume a certain level of care when handling)
I've had DOA monitors that just had a single internal cable come loose during shipping. And laptops catch on fire because of improperly installed cabling.