There are often some clues on the chips that that the inlay is not original. Sometimes you can see an extra ridge or gap between the inlay and the edge of the chip. Sometimes that extra ridge can not be seen though.

I think Paulson/GPI has been aware of inlay replacement as a security problem for a long time, and it is why they have moved to more often using oversized inlays which cover part of the edge mold. Those types of inlays cannot be removed and replaced.