I think he just discovered the idea of bump steer -in the upper picture, the steering linkage pivots are so far out of line with the suspension, any bump and movement in the suspension would have caused it to steer without any actual steering input. In the lower picture, the linkages are much more aligned, reducing the effect.The top photo has the sled set up without any camber, the lower photo with the underslung linkage shows the sled when it has been set up with negative camber. You'll notice he has used the same angled holes and fittings..... only inverted (and I reckon a lot safer because they can't poke you in the eye).