OVERVIEW: At rest, the left surfaces of parallel plates and the length of a rivet shank are both d. After separation, the rivet travels from the left toward the plates at a speed of 0.8c. where a bug waits on the righthand plate.
FROM the PLATES FRAME: The static plates "see" the moving rivet with a shank that is only 0.6 times its original length. Hence, at the moment of collision, the too-short rivet shank will not touch the bug.
FROM the RIVET FRAME: The static rivet "sees" the moving plates with a space between them that is only 0.6 times its original space. Hence, at the moment of collision, the too-long rivet shank, relative to the shortened plate space, will touch the bug.
THE PARADOX: Is the bug touched by the rivet? Yes --- before the collision in one frame and after the collision in the other frame! In fact, special relativity requires that after collision, the rivet shank length increases beyond its at-rest length d. To require rigidity and to reject "rivet-stretching," is to accept the fact that the future affects the present.