Well the damage wasn't caused by just hitting a pothole like most of us imagine. When you hydroplane and ass end gets out, a curb or a pothole it doesn't matter. The ass end got away from you and you hit something 90° off from where the axle expects high loads.
The adjustable panhard bar on my Boss was bent when I went to replace it with the stock one, and I had never hit anything. I did do a 720 one day when I missed a shift at about 70 mph, but never hit anything. The only thing I could think of is that it was bent by a tie down one of the times I took it to a dyno day.
was it bent down or up? if down, i would definitely suspect a bad tie down