I don’t know where you’ve got anything about the steering rack from. The RAC said that they found one half of the subframe wasn’t aligned and tightened correctly. It only presented itself as the tracking being significantly out.
Because your steering rack is mounted on the subframe, there is no way the RAC could check the alignment of the subframe on a breakdown check, if so why did he not just torque up the bolts, also Kiwk fit obviously missed it.
Unfortunately I have suffered a brain injury and occasionally I get confused and often say the wrong thing.