I agree that the wording is poor in this section, however the trained and qualified electrican gets the idea of what the intent is as you have done so. I believe this is a requirement because of the "portable" classification. Storage, movement, and other damage causing effects to the cord-and-plug wiring and to the fixture itself may cause one of these two defects to take place in between use, hence the need to check for these conditions before connecting to a source.
