A patent for refrigerator shelves — yes, refrigerators need patents, too! — called for a "relatively resilient" frame into which the glass part of the shelf snaps. The frame must "temporarily deflect to accommodate the glass". But the frame of the ones Saint-Gobain Corporation made came out of a mold hot, snapped onto the glass part of the shelf, cooled, and thus turned rigid under the influence of lower temperatures.
You see the problem. How can a shelf that stiffens infringe a patent that demands resilience?
You actually missed the bad fact. Saint-Gobain couldn't possibly have infringed the patent when it made the shelf because it did the deed in Mexico, beyond the reach of U.S. patent law.
So why has Blawgletter drawn your eye this far down the html page? Because the Federal Circuit upheld a judgment against Saint-Gobain anyway.
It did so on account of the fact that Saint-Gobain's Mexican customers exported many of the shelves to the land of the free. The court explained:
Properly construed, the "relatively resilient" limitation requires no more than that the frame of the claimed shelf has the structural characteristic of having been temporarily deflected and subsequently rebounded to snap-secure the glass at the time of manufacture. In this case, Saint-Gobain does not dispute that it has imported the accused shelves, and that it has used and sold them in the United States. The end portions of the frames of the accused shelves are "relatively resilient," as that phrase is used in claim 23, in that they were temporarily deflected and subsequently rebounded when glass was being inserted into the frame during assembly.
Gemtron Corp. v. Saint-Gobain Corp., No. 09-1001, slip op. at 14 (Fed. Cir. July 20, 2009).
The patent required the edge of the frame to deflect "temporarily" and "subsequently rebound". It didn't have to keep on deflecting and then rebounding as of the time of importation.
Patently-O talks about the case here.