The T Boss attach point appears to be the primary initiator of the failure sequence.  Upon close inspection, the 3/8" pivot rod had been rotating with the moving piece (read, lack of lube).  The cotter key in cockpit was found in pieces (under the EAR stick on insulation- who knows why I tolerated that invisibility.... out of site out of mind..) Anyway, the rod appears to have been easing it's way West for several gear cycles.  The little bump into the irrigation line trench appears to have been the last straw allowing the East end of the rod to swing freely with the help of the nitrogen strut and bend the 3/8" pivot, unleashing all manor of devilish forces.

 

The fix....  May be nothing in your case.  I believe larger cotter keys, inspection, and annual lubrication would have eliminated the problem.  I seem to remember not knowing much about drilling stainless back in the day.  My cotter key was a wee little piece.  However, there are at least two additional things I am going to do to repair mine.  First, I'll add a grease zirt to the T Boss part so I can get lube to the 3/8" bushings.  Additionally, I'll use a roll pin on one end of the 3/8" pivot rod.  In conjunction with the roll pin will be a slotted mating piece of phenolic.  This will eliminate any possibility of the axle ever turning.

Larry,

 

Sorry for the results you suffered from the inactivity of your HOA.  Surely they have dirty hands in this cruel mishap.  Oops, I didn't want to sling mud into an open wound.

 

Your analysis and descriptions are very useful - and frightening.  Interestingly, during the last century when I was building, I also though that a Zerk fitting would be an important addition to that crucial pivot.  Alas, the thing would have required disassembly and I didn't know about McMaster-Carr at the time.  What I did notice was the thru rod binding because of the welding distortions on the T-pivot piece tube.  I sort of reamed mine out to reduce the binding.  Gulp! I have not lubricated that area in the last 5 years.  Of course, my engine does have just enough leaks to provide the nose wheel well with a fine coating of motor oil.

 

Now for the frightening part.  My through rod is secured like yours and others.  It also hides behind the foot well interior lining.  I think I will pull the lining back and take a look at what is happening with the rod at the termination points.  Uh, it will be a good way to finish up my annual even though I signed it off just last week.