Good question and after rereading my rant I realize I was not terribly clear about that. The "warp" of the mount on the camera was sufficient that when I put the 200 - 400 mm lens on the bayonet mount of the camera body it must have put enough torque on the lens mount to damage it. The 14 - 24 mm f2.8 lens that was on the D4 at the time the camera was dropped also had a bent mount. I was not in a position to actually measure the degree of damage to the mount but the technician said it was pretty serious (eg. there was a 1.8 mm gap between the body and the mounting ring on the body; I could not tell how much the lens mount was damaged).
If I stop and think about it the amount of force that the bayonet mount on the camera could exert on the mounting ring on a lens must be pretty significant. I am not an engineer so I can't even begin to speculate but I would think that there is a lot of mechanical advantage when the mounting surface on the lens and the body come together and are turned to seat the lens. Something has to give if either the lens or the camera mount has been damaged and the two are brought together to be attached to each other. That apparently is what precipitated the damage to the 200 - 400 mm lens when I made the mistake of attaching the lens to the damaged D4 mount. Why it happened with the long lens and not the other lenses that I mentioned I cannot explain. It is just good fortune that the other lenses were unaffected.
I have really learned the hard way just how dropping a camera can lead to unrecognized damage. If the impact is significant it is best to have the professionals examine the camera/lens just to be sure that all is well before continuing to use the equipment.