GM received a single report from a mechanic of a missing brake pad on a rental Chevy Sonic. They investigated, found some kind of root cause, and out of precaution recalled ~5000 Sonics manufactured around the same time for inspection. (and estimated 20-30 vehicles were affected - it'd be interesting to see how many turned up)
Tesla's response thus far is miles apart. Nothing about it gives me confidence in their QC.
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.