Honestly, I know exactly what happened. The bolt sheared due to the bogeys bottoming out on the Motolink swing arm. And when the bolt sheared, I lost the bogey on that side. I had a shorter bolt that I could slide in the end and gorilla tape in there to make it off the hill but since the bogey was gone , the track clips contacted that part of the aluminum shaft and wore a groove.
As far as the sliding bushing goes, I have no idea why it failed unless that bottoming torqued it somehow. Or when the track came off several times and forced the skid sideways it might have stressed that yoke and fatigued the shaft.
Probably the side torquing. I broke mine at standstill trying to get bike out of a trench. It's a little too fragile part. I suggest they make them with more radius to the transitions on the part, it's obviously a stress riser in that area and they snap.