The root of your problem is laterall movement of the brake rotor causing the pads to move in their mountings.
The question is why. The most common treason for this is simply distorted rotors or dirt and rust in the mounting surface area. I find it strange that no one has found that. The use a a dial indicator on the rotor will prove the theory. Any more than .005" movement is too much.
In rare instances, this could also be caused by a bent flange on the wheel hub, but that would be very rare and would have to have been caused by a collision of some type.
No, it's not the anchor bracket.
It is possible that there is a problem with the rattle clips also but i think it's a rotor problem.
Tell him to uses a dial indicator on the rotors with them bolted down securely to measure the runout. It's going to be a rotor or rotor mounting problem. It doesn't mean anything thhat they cut the rotors, in fact that may be how it happened. The cut is only as good as the guy that mounting them. If they aren't mounted on the lathe straight, they won't be cut straight.
Once you have accepted one of my answers, you will have the option of requesting me in future questions.
I would also use my name in the title to be sure other experts see it. If your planning on doing it now, I will watch for it.
I assume your taliking about the same vehicle so it will be in the same category. i have a different name in other categories.