Quote - > Quote - 1)   All "Map" strings are followed by "NO_MAP", and searching for "jpg" and "Textures" both returned nothing.

Then it is hard to see how your tester could be getting texture calls.

It's possible that if the tester is using P7 or P7SR1 that if you've used either ":NO_MAP" or "NO_MAP" (with the quotes) rather than just NO_MAP (without quotes).
This was dealt with by P7SR2 (P7SR2.1 also fixed some other weird cases, but these don't appear relevant).