It seems clear to me that your installation is code-compliant. The intent of 411-4 is to forbid the installation of low-voltage cables throughout the home. Since you are using a wiring method included in Chapter 3(Nonmetallic Sheathed Cable, Article 336 & Flexible Metal Conduit, Article 350 , but you already knew that.) and I assume using both within their acceptable installation parameters, I see no reason to fail your job. Can you call another inspection agency, or does your town use their own Code Enforcement Officials?