I see, like a lizard's tail
https://www.dpreview.com/forums/thread/2280430
if i am not mistaken, this is the post that started the minor panic
it was early 2008.
i cannot reveal who told me but this part was silently reinforced by Nikon.
The lens i
s designed to break like this when it is exposed to strong impacts. There is no design error or flawed construction.
This saves the camera and in particular the mount and mirrorbox from damage. The broken lens is fixed on a Nikon repair centre in 10 minutes. They just put another rear part onto it and replace the broken signal cable.
I have a stack of the sheared-off rear parts provided to me by my Nikon repair tech. It is a source of spare bayonet mounts (and CPU contact blocks).