Smooth is not good. Try it for yourself to see the difference. Rerod can be quite the challenge compared to smooth cold role or similar.
I did not read the article, but is it possible you misunderstood? Could they have been using a section of conduit to which a section of wire is added?
I understand your concern and I would not try out what you have described in a trapping situation until I would have tested it a few times in the yard. Just off hand, it sounds as if the conduit is of one time use since it gets deformed. That is a big negative right there.
You are also correct in that bad information is out there. However, I would not expect to find it in a serious trapping magazine or forum. Too many experienced trappers would point out the error and the publication would lose credibility.