because it's a single incident, there is nothing to recall.
Your point about “they must have the parts in the country” is a valid one, but it’s probably not going to be just a forgotten pad that they’ll need to slap in there. As a shade tree mechanic, if I’d somehow put my car back on the road without a brake pad, I’d do more than that. I doubt Tesla’s going to think differently with liability on the line.
I don't do my own brakes and don't know about the caliper, but rotor replacement is pretty routine, I thought. They usually resurface them whenever they replace pads, and replace them once they get too thin. So having no spares seems a little bit too JIT for a car company.