We recently encountered the situation of counterfeit LCD panels. Of unknown manufacturing origin these panels were styled and labeled to copy a well known manufacturer. I am told that there was nothing to indicate these were fakes, the labeling was a perfect copy, until they were connected and switched on – not only was the timing off from specification but flaws in the actual display became quickly apparent. No doubt the characteristics of such counterfeit panels will vary so it is not worth being too specific.
The bottom line message from this is that counterfeit panels exist so it is important to be able to trust the source, much the same as with electronic components.