I assume you are referring to the transition where a threaded coupling was used to transition from Sealtite to pipe.
I even have seen a statement by UL in print that claimed that such use of the threaded coupling was improper .... but it was hard to be sure. UL has engineers, not writers, and their prose is often poor. (Just look at any of their standards!)
It's certainly a matter of lively debate in some circles. Alas, the most strident voices of opposition seem unable to back their opinion with more than their egos.
Personally, I don't have an issue with it at all .. and certainly not when there's a ground wire in the run.
As for the argument that "you can't make a piece from parts that is factory made," I have nothing but contempt. Indeed, the 'factory' stuff is usually inspired by the successful use of a field-made assembly.
