On a new designer-residential home build, where the walls were all core-10 steel (yes, very odd) I ran EMT down the walls from a drywalled-in joist-bay lid for a couple of the switches and outlets on some of the exposed-block internal walls. I had the romex from within the lid going into the EMT (with proper fittings and clamp connectors), leaving the exposed portion of the run in 3/4" EMT down to the surface mounted switch & outlet boxes.
The inspector tagged me on it, saying you can't run romex in EMT. I actually went down to the city with my NEC and Illustrated NEC and tried to show him the Chapter 9 Note 9, which specifically provides fill provisions for running multi-conductor cable through conduit, and he wouldn't even look down at the book. He just looked at me and told me NO. Wouldn't listen to a word I had to say. It was clearly an ego thing, and there was nothing I could do about it.
I had to put a junction box in the lid near the EMT, run flex to the EMT, and then pull in single conductor THHN into the switches and outlets.
I'm still wondering what that was all about. The very same guy had nothing but great things to say about my EMT and panel work, but it sure seemed personal at the time.