Some of you may remember my recent reviewof the 8264 Hauler. In that review, I was looking at the new solid panels and made the following observation:
Since I am unwilling to let anything go unexplained, I have been racking my brain on this one and I believe I have come up with the answer. On a normal Technic liftarm, beam, or brick, the holes have a slight countersink. This allows the interlocking flange on the end of the mating pin to snap open into place and remain firmly attached. The countersink prevents the pin flange from protruding beyond the face of the part. In the case of this panel, the entire surface is moved back instead of using individual countersinks. Why? I believe that the reason is so that the parts can be removed from the molds. A normal beam can have the die on either side parted to release the part. In this case, since these features face inward, there would be no way to release the mold from the part if the faces were not planar (unless you had an expensive collapsible mold).
There you go, mystery solved. You may now go back to your lives without this question continually nagging at your brain.