Haveing done both commercial and residential work in the resi panels I have used the romexconnectors and stapled accordingly. In the commercial end we usually used conduit and ran mostly thhn. I have had feeders for the resi panels in a pipe but not the romex as you describe with them in a pvc pipe. Cant see how the inspector can fail you if you use the romex connectors. Why he said he would fail you if you dont do it his way is beyond me. Check the NEC Book point out panel installations and if you have to call the inspector on this one with your boss backing you up. Just be sure your right before you call him on this one. Also be sure to use the staples that can handle 2 romexes to be stapled together. Most inspectors wont fail you for useing the blue ones but he can call you on the blue staples.
