Thanks for those pictures, Kurt. The last two from your site show exactly what I was wondering about, part of the bracket cantilevered past the edge of the tube, putting a little flex into the part of the bracket in the HAZ zone. I would guess the car in this thread was well on the way to failure by the time that pot hole was run over, so it wasn't a real issue, just a distraction...
Which is why if you run on tracks and compete, looking your car over is a good idea. Not just going around and torqueing bolts all the time, but actually just looking at it. For me that works best if I pick different parts of the car on different days and look at that part more carefully. The idea is not to see what you always see, but to notice something different.
I learned this doing preflights when I used to fly. Every time I did the preflight I picked the next area from the previous preflight and looked a lot more carefully at it. One day I got down low and looked up under the cowl and saw that the nose gear was coming off the plane! It was held on by a clamp and both nuts were so loose I could see half the threads on the inside of the nut!
That day, I won big!
The trick is try to look at the parts like they are not familiar. Carefll inspections are great, but just being in the habit of looking at your car when your standing near it or walking up to it can find lots of problems. You see people driving down the highway with half the air missing in a tire! Everyone can benefit from learning just to look at their car...