The toe link is deformed.
The shaft clunks when the wheel rotates.
Using all of the track including the turtle back may have had one or both rear wheels off the track. Coming down on one wheel could cause a dual failure. We have not torn it down so we are not sure the clunk is the CV. Is it the wheel bearing, differential, bent shaft? Our track side evaluation is the CV.
Did they occur together? We have front facing video that shows the shudder at the same time loss of control occurred. Bruce knows first hand the car was perfect, glued to the track right up to the loss of control and simultaneous clunking. We know toe links don't clunk. The clunk is in a rotating assembly.
We'll tear it down and see what we see.